'Just hug him” was the half-serious advice I got from a sympathetic Tory grandee about how best to approach David Cameron after his worst week as leader of the Conservative party.

When I caught up with the leader of the opposition he didn’t look like he wanted affection. He was still pumped up with adrenaline and anger after his bumpy ride at prime minister’s questions last Wednesday when Labour MPs jeered his return from a disastrously timed trip to Rwanda. Under the permatan Cameron is cool and fierce. I would sooner have hugged a hoodie.

Amid place names in his Witney constituency that might have inspired J R R Tolkien’s hobbit country - Buckland Marsh, the River Windrush, Ducklington and Standlake - we waded through sodden Middle England, fields transformed into lakes, roads into canals, houses into fishtanks.

Most of the locals are friendly little hobbits: sweet old ladies forced out of their care homes by the floodwaters, stoical small businessmen and hard-working council employees. In Kelmscott we wade over to Kate Moss’s rural pub, the Plough Inn, cut off by the overflowing Thames. It is closed and for now Kate & Co have to get their kicks elsewhere. As we wade on Cameron sees a £60,000 BMW caught in the rising waters and instantly wants to offer help.

“Go on, let’s do something useful. Let’s help tow that car,” he says decisively. What better example of community spirit at work untrammelled by the ineffective, interfering state?

Alas, the object of his concern is no hobbit but a troll. “Why don’t you f*** off. You are just making political capital,” says the angry man wading towards us, as if he had long chewed over this sound-bite before spitting it out. Cameron stays commendably calm.

“For God’s sake keep your window up,” shouts our nononsense blonde driver, a West Oxfordshire council official called Kath, as we are obliged by the rising waters to reverse past the troll again.

“Dead-in-the-water-Dave” has been hit by two by-election defeats in which his party came third, and by plummeting poll ratings both personally and for the Tories. There are anonymous rumblings of discontent on the back benches and catcalls from right-wing columnists. Forget election victory - “at this rate they won’t even score second prize with a hung parliament,” snarled The Sun.

“As far as I am concerned the next general election should come as soon as possible,” Cameron says. Is he in denial?

Gordon Brown seemingly walks on floodwater. The failed terror plots and a disdain for the flashier aspects of Tony Blair’s legacy have done him no end of good: at no political cost he has binned the Manchester supercasino, signalled getting tough on cannabis and promised to deport more foreign prisoners. The Daily Mail lapped it up.

Cameron’s response is: “If you tailor everything to what a newspaper says every day, you are lost. I remember huge editorials saying that if I was not the devil incarnate then I was at the very least his younger brother. You have to be resilient.”

Not every ally in Fleet Street is lost. He wins friends by demanding a referendum on the proposed changes to the European treaties, which in his view means the reintroduction of the hated European constitution. That certainly is a switch. He used to criticise Tories who kept “banging on about Europe”.

Is that a backward step, given that people are suspicious of one-note Tories? “No, it is not backward-looking,” he says. “What is backward-look-ing is the mindset that ‘we change the rules in Whitehall without your permission’. I will fight this very hard. Gordon Brown will look very weak in not granting a referendum.”

As for his rebels, the Tory leader by all accounts dealt briskly with his 1922 Committee of backbenchers, which he faced on his return from Rwanda. He tells me he made light of his poor relations with the right-wing Cornerstone group of MPs who are critical of cuddly Cameronism. “In Rwanda I saw a sign on the road saying, ‘Come pray at the Cornerstone chapel’. It is a broad church but I didn’t go in.”

But is he really running to win this time and hasn’t he lost momentum? And are his backbenchers just too barmy an army? Some of them are so detached from reality that they daydream about losing an early election to get rid of him in spring rather than suffer a defeat years hence.

“Last week the Conservative party produced a report about poverty which shows it is serious and compassionate about trade and aid,” he says. “This week you saw Gordon Brown stand up and announce a whole series of measures - whether it is a national security council, a border police force, questioning suspects after charge, proper integration for British Muslims and others - all of which we had carefully thought through in an 18-month policy process and announced before him.

“This shows we are serious about government and making the changes Britain needs. So when the smoke clears you see a very strong Conservative opposition making the running on important issues, and with the unity and drive to form a government.”

The charge is that Brown is all spin and the Tories are the substance. Cameron sneers that the theft of his border police plan is cosmetic without the vital involvement of existing police. “We think it through. On terrorism Gordon Brown makes policy in haste and repents at leisure.”

However, Cameron believes that people will come to see he is setting the agenda, not Brown. “We have a clear plan and a timetable for announcing our policy reviews and, more importantly, a clear mission in times of recognising that the big question in politics today is mending Britain’s broken society. It is a question people want answered. We are the ones coming up with the ideas.”

Why won’t Brown support the family through the tax system? “I think he is wrong and he is muddled. What is progressive about broken families, about more children in care homes? It is progressive to give people a better start in life.”

Has the sheen gone off the Tory revival? “I know polls do come and polls do go. I have had poll leads, big ones, small ones, poll deficits. I know it’s a cliché but what matters is when real people vote in real politics. In local elections we reached over 40% for the first time in over 10 years. Not enough, but a very, very good process.

“That was a coalition coming together of traditional Conservatives but also people who previously voted Liberal or Labour or not at all, recognising the party as a serious alternative.”

The nub of his point is: “We know the approach of being on the centre ground, of hitting the issues of NHS schools and crime, is what people want and if we do that with purpose and tenacity we can win.”

The Tory leader is most fierce in his insistence that a thread runs through his agenda right back to his leadership manifesto worked through with his strategist Steve Hilton and the shadow chancellor, George Osborne.

“I have been rereading it briefly,” he chuckles – and insists he has never wavered in his themes of social responsibility.

“You have to start with a world view. An explanation of why Labour has failed and why you will succeed. It is not enough to say, ‘You spent the money, where are the nurses?’. You have to explain why the nurses aren’t there; that top-down state control has failed.”

On the charge of underestimating Brown he replies with asperity: “I didn’t think it would be a walk in the park.”

Did he surrender the Conservatives’ best card, law and order, to Blair and Brown when he gave his “hug a hoodie” speech? “Those three words were never uttered by me. The man who did is now working in my office. I am a forgiving sort of chap. Everyone knows the Conservative party is a law and order party.

“I firmly believe individuals must take responsibility for their actions. But there were two ideas I wanted to get across. We must have police reform by cutting paperwork and the underperformance by some officers. But we also have to deal with the underlying causes of crime. When you explain this to a Conservative audience, you find so many involved in remedial schools, charities, prison visiting that it is meat and drink to them when you explain it.

“It is true that there are many children who lack strong families and do not have enough love. I don’t back away from that. It is true. Kids Company and the other organisations are substitute families of mutual support and love.”

On foreign policy and defence he aims to shift to attack mode, too. “Learn the lessons of Iraq. Liberal democracy can’t be dropped from a distance of 45,000ft. Order and stability must come first. A bit of scepticism is needed in the mix. Tony Blair’s foreign policy was liberal interventionism, without a reality check.”

Cameron will be turning his guns on the Ministry of Defence’s army of 98,000 civil servants and their gleaming headquarters in Whitehall, while the real British army is starved of arms and men.

I put it to him that the Ealing Southall by-election was an organisational disaster, that oppositions cannot afford to fail through poor staff work. Cameron was needlessly exposed by the poor choice of Tory candidate, paraded for the cameras five times in a seat never won by his party and had the campaign ascribed in party literature to “David Cameron’s Conservatives”.

Ditto booking a Rwanda trip in parliamentary time. There are divisions on these issues even within the notoriously tight Notting Hill set. He accepts ultimate responsibility: “I don’t blame my staff. I carry the can for it.”

But hasn’t he been devouring Alastair Campbell’s diaries like the rest of Westminster? “I dipped, but it was like drinking multiple espressos.” An inspiration? “The Alastair Campbell model is not one I’d like to follow.”

What Campbell does teach is that contrary to received wisdom, you must not wait for the government to lose an election, you have to go and fight for it, 24 hours a day, seven days a week. Cameron promises that the Tories will now be fighting all the way.

Perhaps both Brown and Cameron are too much natives of little Britain. Neither seems to have heard this tale from Europe: when the Elbe flooded in Germany five years ago, Gerhard Schröder’s fortunes were at rock bottom. With furious energy he mobilised a nation’s resources and won reelection soon afterwards.

During the great British floods, however, Cameron was out of the country at the crucial moment and it’s no consolation that Brown’s response, too, was belated. An effective intervention here would not have been a stunt but a potential winner.

Cameron, with his impeccable green credentials and a ready-made critique of how new Labour and Whitehall bungled our flood defences, has a good story to tell. He has missed an opportunity to tell it.

Few such opportunities are granted to those who stand and wait.

How Cameron’s stock has sunk

David Cameron knows what it is like to have a bounce in the polls. When he took over as Tory leader in December 2005 his party was convalescing from its third successive election defeat. But the Cameron honeymoon gave the Tories an immediate opinion poll lead and, from early 2006, their first sustained period ahead of Labour for years.

Everything appeared to conspire against Labour; Tony Blair’s tiredness contrasting with Cameron’s freshness, as Iraq and cash for honours took their toll.

Some wise Tory heads warned this could change with Brown’s move to No 10, but few were prepared for the scale of the shift.

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