Everything Sir David Murray has achieved in his life can be set against the day 32 years ago when, aged 25, his car ploughed into the base of a tree outside Edinburgh, an accident that cost him both of his legs. This week, asked yet again about his remaining motivation at Rangers after 20 years in charge, the Ibrox chairman placed his life in a graphic context for his inquisitors.

“I'm probably more motivated than any of you because of my circumstances,” Murray, who saved his own life 32 years ago by tying tourniquets around his crushed limbs as he sat amid the wreckage, said. “When I get up every morning I have to face things that none of you have to face. So never worry about my motivation or dedication - I have as much of these as anyone. I've had a rollercoaster of a life, with good fortune and bad, but I think I'm good under pressure. And I hope to deliver more success for Rangers.”

Graeme Souness, the man whose friendship with Murray originally triggered the steel magnate's purchase of the club 20 years ago this weekend, once said of Murray: “When I look at David, and see what he has been through, I just think, ‘This guy's got guts.'” Arguably, however, Murray has required endurance and patience more than anything to survive 20 years of storms at Ibrox.

In recent times Murray and a beleaguered Rangers board have been overcome by a near tidal wave of problems: the exciting rise and sudden fall of Paul Le Guen, a lack of success on the field, and an on-going image problem with a section of the Rangers support who, in Murray's eyes, provide humiliation for the club on an almost routine basis. The Manchester riots following the Uefa Cup final in May were almost a last straw and it is little wonder that, in his heart of hearts, Murray has had his fill of Rangers and would happily sell his 92 per cent stake to an appropriate - or even willing - buyer.

“I'll leave Rangers when it is right and correct,” he said. “The recession hasn't really set that plan back, it is just all about value. I have put well over £100million into the club and I won't get that back, I accept that.

“[Buying Rangers] would be a sound business investment for someone if they wanted to run it their way. I've run it my way, which you might want to say was financially wrong, but their way might be financially prudent. It depends how deep their pockets are.”

And is there, in these hard-pressed times, a likely buyer out there? “I don't want to pre-empt that,” Murray said. “If it happens, it happens. I don't want to lay down a whole set of criteria, other than that the person who buys, I hope, will have the best interests of the club. Like I say, I won't get my money back, that's now irrelevant.

“The deal has to be right for Rangers. There's no point in me selling to someone who has to beg, steal and borrow just to pay the entry fee, and who can't enter the race. So I'm still here, and I might still be here for some time, who knows?”

As with any football club, the Rangers support has its factions. A healthy majority applaud Murray for his efforts over the years but, in the internet age, there is a small, angry, disenfranchised-feeling group who want Murray out. A permanently-irate rump who swarm around websites regularly calling for heads - among them this reporter's as well as Murray's - have recently come to receive the Rangers chairman's scorn. Such breeding grounds may be the subject of mirth and ridicule in the media but Murray views them - with their bigotry ever lurking - as an occasional poison infecting Rangers.

When I asked Murray about that group of Rangers fans who feel he has “over-stayed his welcome”, his reply was withering. “Well I say, maybe they've over-stayed their welcome,” he said. “And I think it is a small rump. You know how these websites work. It's the same guys sitting in the middle of the night sending e-mails to themselves. And then they start a thread and it says that you are gay or that I'm an asset-stripper. You all know how they work.

“I'm an asset-stripper? I've never been able to work that one out. How can you asset-strip yourself? I own 92 per cent of this club yet I'm an asset-stripper! I think we all know what these websites are like. And you know what? I know these supporters. I identified some of them and I went to meet them. And they were like mice. So I think for any individual to use a nom de plume on a website, and call me an asset-stripper, and all these other things, is totally wrong. I don't think these people have much credence.”

Such aggravations aside, Murray's 20-year stewardship of Rangers can be split into two distinct halves: an opening ten years of sumptuous success, when he rode a wave of popularity, followed by a second ten years of mounting afflictions. Certainly, two Scottish Premier League titles in the past eight seasons is not good enough for Rangers, and provides ammunition for those who argue that Murray's time is up.

The Rangers chairman enjoyed a stunning two-year period after his appointment of Dick Advocaat as manager in 1998, and Walter Smith subsequently returned to Rangers to bring relative success and a Uefa Cup final last season. Yet there is no doubt what Murray's biggest disappointment is. Le Guen's arrival at Ibrox in 2006 appeared to be a fantastic coup for the club - the Frenchman had been chased by clubs all over Europe - yet it became a disaster.

“I always tried to change the menu with the players and managers here,” Murray said. “I brought Dick Advocaat in and it was a success - then, amazingly, Dick ran out of steam. Alex McLeish was able to take on his players and win a treble. But Paul Le Guen is a real disappointment because there is no doubt he was the most chased manager of the time.

“I went to Dinard in December [2005] to meet him. I told Alex McLeish what I was doing. I said, ‘Look Alex, I think it's time for change.' So Martin [Bain] and I flew to Dinard, we were on a private plane and the weather was atrocious. We were the only plane to land that day and there was nobody to take us from the airport. I had to climb on a Landrover trailer that belonged to the fire brigade. I said to Martin, ‘I hope this bastard is good!' Funnily enough, it wasn't a very good first meeting - Paul was quite cold.

“But we brought him and his team to Edinburgh one day to discuss things. He had all the credentials - it was a big coup, not just for Rangers, but for Scottish football. But when Paul came here I don't think he prepared himself for what he was coming to. I don't think he understood the game, and the players he bought didn't make the grade.”

Murray also chose to nail one of the enduring myths about Le Guen's departure from Rangers - that he was sacked, rather than the Frenchman choosing to leave on principle. Le Guen has always insisted he made the decision himself to leave Ibrox.

“Three weeks before he decided to go Paul sent me a text saying, ‘Thanks for your support',” Murray said. “I thought, ‘That's fine, he's OK' and then he and Barry Ferguson had their fall-out. I was in Paris, in a brasserie having a glass of wine, when I got a call saying Paul had dropped Ferguson, so I flew back immediately.

“I met Paul and he told me he would like to go. I said, ‘OK, just sign this bit of paper' because he had two years left on his contract, and I took the view that if he wanted to walk out, and we were letting him go, we shouldn't be financially paying out. I don't know if he had been tapped up by Paris Saint-Germain - he said he wasn't - but I have to say I had a great working relationship with Paul. We tried something different and it is a big regret that it didn't work out.”

Financially, by his own admission, Murray has been through his ambitious and reckless phase with Rangers, when he “chased the dream” of Europe. These days he is far more sober-minded about how it should be done. Frustration, though, lingers when he compares the past with the present at Ibrox. “When I first came in we could buy the biggest players in England - we could buy the John Terrys, the Frank Lampards,” he said. “But that has gone from us now. The financial restraints on a club like Rangers are phenomenal. The debt between the teams competing in the Uefa Cup final - Rangers and Zenit [St Petersburg] - was £15million. The teams in the Champions League final had a combined debt of £1.2billion.

“It is not a level playing field now, we can't compete financially. So my frustration is in not being able to take the club to a higher level. We are restricted by playing in Scotland - we just compete with Celtic every year. It is a foregone conclusion now between Rangers and Celtic, which makes things not as interesting as they could be.” Rangers, warns Murray, may have to remain on a frugal course for some time to come.

“It's not a question of throwing money at it - I've invested enough money,” he said. “Rangers as a club is fine, but this is the wrong year to be spending money when, first, we've gone out of Europe, and second, there are these current financial restrictions.

“I think we will reduce the size of our squad and bring in younger players to make up the balance of that squad. If we don't start doing that, there is no point in having Murray Park. Right now, these are the basic economic realities.”

Yet the theme that besieges Murray, despite all Rangers' historic success, remains his biggest aggravation: bigotry. The debate is complex - and some believe, including Murray himself, exaggerated - but enough poison is still out there to ruffle the Rangers chairman's feathers as he tries to protect his club.

Murray, it must be said, deserves credit for speaking out against a core of his club's fans, when life could be much cosier for him if he simply kept quiet. “Years ago we signed [Maurice Johnston] as a football player first, but also to break the tradition of this club not signing a Roman Catholic - that had been wrong, we did the right thing, and that situation has improved beyond all measure,” he said.

“But there is still a rump of our fans whose behaviour is totally unacceptable. In Manchester there was no excuse for what happened, you can't defend the behaviour of some of our fans. In some ways it was unfortunate that the Uefa final was in Manchester - it was too easy to get there. We were happy to be in the final, but Manchester wasn't ready for the party, and a minority spoilt it for us.

“You can talk about good PR but it's quite hard to stick up for people behaving like that. We have an element in our support whose behaviour is totally unacceptable, but there are only so many times you can say, ‘It's unacceptable, it's unacceptable.' Having said that, there are more important things going on in society than bigotry. I hope there's no one in Scotland dying because of sectarianism, but there are certainly people dying today because of drug abuse and obesity. I do think Rangers have become a soft touch for many of the politicians. We're not denying we've got a problem but some people seem to put all the ills of Scottish society on Rangers. Get off our backs and let us play football.”

After 20 years, it has all proved quite a remarkable journey for this remarkable man. “I came into something of the unknown at Rangers and am the longest-serving chairman in the club's history,” he said. “I have been here for 15 per cent of the club's history and won 30 trophies. It's not bad, it has been quite amazing.”

McCoist as next manager

Sir David Murray has admitted that he hopes Ally McCoist will be the next Rangers manager - if circumstances allow him to become Walter Smith's successor.

A lot, says Murray, will depend on Rangers' success over the next two years, but McCoist is clearly the chairman's favourite for the post. “I would have thought, all things being equal, and if Walter is successful, that his natural successor would be McCoist,” Murray said. “It has not been talked about, but it is an understanding, and I hope that Ally gets it.

“It will be a success-driven thing. I suppose if we go through three years without winning the league, we will be under the same pressure as every other club.

“You wouldn't have thought [McCoist could be a manager] 20 years ago but he's a very strong boy. He has a strong mentality. He is bright, and he and Kenny [McDowall] are a good team.” Murray said that both he and Smith had jointly pushed to get McCoist back to Rangers in January 2007.

“Walter and I discussed it - Ally coming back here - because, hopefully, we would get back to a successful period,” Murray said. “It has not been talked about, though we did renegotiate McCoist's contract at one point. Ally didn't come back to Rangers for money - he came here for a lot less than he was earning. He gave up a lot to come back.”