Long before José Mourinho arrived in London and seduced a nation with his coat and copper-bottomed arrogance, another self-styled “Special One” was dominating the sporting vista with his T-shirt and two fingers. Daley Thompson was the irreverent icon who baited Carl Lewis with politically incorrect slogans, told the press to p*** off and talked of “The Big G”. For honest opinions, he is still the man.

Let us start with Dwain Chambers whose presence at the Aviva National Championships and Olympic trials in Birmingham this weekend casts a shadow over the rest of the field. Forget the self-righteousness of both sides and listen to a man who will call a spade a spade and then beat you over the head with it. “A whole load of people are complaining now, but they didn't say a word when he came back in 2006,” Thompson said. “People are just using this for their own ends. They want to be seen to be saying the right things. There are a lot of two-faced people out there.”

Before Chambers's legal team considers Thompson as an expert witness, it should know that he supports the BOA bylaw banning doping offenders from the Olympic Games. Not that he signed the British Athletes' Commission (BAC) petition backing it. “I wasn't asked,” the former decathlete said. “But you did not see an interesting name on it. I've never heard of them [the BAC] anyway.”

And drugs? “It was worse in my day because it was state-sponsored. Now it's just pockets of people. Wada [the World Anti-Doping Agency] and the governing bodies need to stand up and be counted. A two-year ban? What is that? They're not taking it seriously.”

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Is athletics irrevocably tainted? “We suffer because we're more successful at catching the cheats than other sports. We should celebrate that.”

Thompson is neither apologist nor bitter former pro. He loves the sport, highlighted by his work with the Sainsbury's English Schools' Championships, which are taking place in Gateshead this weekend, but highlights the flaws. He said that he and UK Athletics are “poles apart” in what they believe is necessary to improve the sport. “We need to get into the schools and homes and drag people into the sport to show them why it's so good,” Thompson said. “And the best advert are the Olympic champions, but they aren't used.”

He believes that too many people are concerned with protecting their own interests rather than seeing the bigger picture. “That's OK because most of us [Olympic champions] are not prepared to get involved with the politics,” he said. “If it was straightforward, you'd probably get 50 per cent of us helping out, but it's not.”

A recent poll by Camelot failed to include Thompson in a list of Britain's top Olympic heroes, which may reflect his criticism of the lottery system rather than his two Olympic gold medals, which he famously referred to as “The Big G”. He seems bereft of bitterness, although when asked if any of those athletes gathering in Birmingham excites him, he said: “No.” One of the problems is modern life. “My old coach, Bob Mortimer, says he gets kids coming to him who can't do half the things we could,” Thompson said. “When we were 15, we thought we could fly.”

Yet for all the science and funding, Thompson said that success is “nine tenths genetics”. He points out that Britain went from a dire 1976 Games to a golden era four years later. Could it happen again? “Maybe. Talent is out there, but it gets lost. I see promising kids but never hear of them again.”

So perhaps the most pertinent point regarding the future of British athletics is not whether Chambers wins tomorrow, but whether those wannabes in Gateshead ever make it to the Olympic trials.

- Daley Thompson is a representative for the 2008 Sainsbury's English Schools' Championships.