Ann Widdecombe: The lady's not for turning – but will her party turn to her?

It was a terrific performance, "A Morning with Ann Widdecombe". Across the Home Office brief and out to the wider shores of politics and social affairs, she believes she has always been right. She feels vindicated on asylum-seekers and she has not changed her view on cannabis, section 28, positive discrimination for women or any of the other issues on which the "modernisers" want to move the Conservative Party to the socially liberal middle ground.

She may be blonde ("nature was turning me white and it is much easier to keep white hair blonde than it is to keep white hair dark") and she may have lost weight ("for my health") but: "I am still Ann Widdecombe. I am still a Catholic. I am still a Tory. I still believe the things I've always believed in."

By the end of the morning, her impatience with the present leader of the Tory party was bursting through the proprieties. "Winning the next election is very uphill, terribly uphill but there is no law of nature that says you can't walk uphill. What's happening is that we are sitting at base camp arguing about the route up that hill – instead of just starting on the hill. At least start on the hill. You cannot conquer a mountain from base camp."

Earlier, she had been polite about Iain Duncan Smith. "We have a fine leader who is going to be Prime Minister." And she accepted that she could not be leader. She may be a television celebrity, loved by the Tory grassroots but, two years ago, she could not even rally enough support from MPs to enter the leadership contest. Could that barrier ever be overcome? "I think the answer is 'No'."

But she cannot quite conceal her eagerness to be back on the front bench. She said she does not want a Shadow Cabinet job "for the foreseeable future. There might be a time when sheer duty calls. But I do think duty calls the other way at the moment, and for at least another year out." Only another year! That will have an ominous ring to the ears of Oliver Letwin, who took over her post as shadow Home Secretary after the last election.

This month could be the start of her comeback. It all started with a typical example of her tenacity. She wrote to the Home Office asking it, under the Data Protection Act, for all the information it held on her.

Among the reams of paperwork supplied was one gem – a memo from an official to ministers, written two weeks after 11 September 2001, discussing the ease with which terrorists could gain entry to the UK by abusing the asylum system.

It said: "Unpalatable as it may seem to you, the only way around this is to adopt Ms Widdecombe's proposal to detain all asylum-seekers at least until they can satisfy us as to their identity, age and nationality."

The timing of her find could not have been more apt. Two asylum-seekers had just been arrested in connection with the discovery of ricin in Wood Green, north London. "Under my system, people who may have been running round the community making ricin would still be in detention, and I know where I would rather have them," she said.

Three days after the memo was published in the press, DC Stephen Oake was fatally stabbed in Manchester in an anti-terrorist operation to arrest a man whose asylum claim had been rejected. The next day, Duncan Smith raised the "Widdecombe memo" with the Prime Minister and asked for an assurance that Britain's borders would be made secure. It seemed the Conservative Party had returned to the policy of detaining all asylum-seekers on which it had fought the 2001 election.

But no. Mr Letwin conspicuously failed to pick up his leader's cue. He would adopt the Widdecombe policy as a last resort, he said, but added: "I hope we can find a more radical, more effective, less draconian solution."

The Daily Mail, and many in the Shadow Cabinet and wider Tory party were furious. Mr Letwin had seemingly been staring at an open goal and, instead of scoring, passed the ball to the liberal pinko Independent types to take to the other end.

Ms Widdecombe relished the challenge of taking on her successor's views, as reflected in The Independent's editorial line. "Anybody in the world can come here, utter three words, 'I claim asylum', and regardless of who they are or why they are coming, they can then be totally free within our community. I don't think that is responsible, particularly in the present climate, or practical, or even moral."

She is not interested in the European Convention on Human Rights. "All these things are resolvable. You either deal with it through a derogation, or you deal with it by amending your own law. You deal with it. You don't sit there and say, 'Hands up, there's nothing we can do.'"

Belgium and the Netherlands detain all new claimants – although not indefinitely. "I have never proposed just slinging people behind barbed wire. You've got to be able to provide a decent education and all the rest of it." Did she think the Australian policy was decent? "I don't know. I do know that Harmondsworth is wonderful."

She argues ferociously that her plan would cost less than alleged because it would deter people from coming to this country in the first place.

More important, I thought, was that it was wrong to detain so many innocent people for potentially long periods without trial. Nor, with 90,000 arrivals in this country every year, would it stop terrorists.

"We are going to have to agree to differ." I had been prepared to concede that at the start, and was proud to make it to what I counted as a score draw. She, on the other hand, was majestic in her certainty; triumphant in her conviction that she had seen off another moaning liberal minny.

But it is not just against The Independent she has to argue. Why has David Blunkett, the Home Secretary, regularly excoriated for his authoritarianism in our leader columns, not implemented her policy? "Pique and pride, because it's our policy. Detention was a major and a massive Conservative policy at the last election." I doubted this was enough to put off such a determined populist as Mr Blunkett.

She certainly thinks she is fighting a winning battle. As the shadow to the shadow Home Secretary, she must be more of a threat to Mr Letwin than anyone on the Labour side of the House. She praises him with deadly condescension as "a brilliant brain", and predicts that, at the next election, the Tories will advocate the detention of all asylum-seekers.

"On asylum, crime and tax, I wouldn't be at all surprised if in 2005 the manifesto that we fight on is the same under another name as the one in 2001."

Ambition still lurks. Twice in the interview, she accidentally referred to herself as Home Secretary. But no, she has not had a makeover. She is as worried about the cult of physical perfection as she ever was. "It marginalises the spiritual. And when young girls of eight or nine start getting anorexia because of the slimming craze, we ought to pause."

But she has no regrets about her appearance on Celebrity Fit Club. She needed to lose weight for health reasons. But she did worry that serious politics would be undermined by her celebrity. "I find the opposite is true. People need to relate to politicians as human beings.

"Television is immensely powerful, and if you can see people in a non-political context, it can work wonders. The way we used to do that was the old-style public meeting."

Hence the success of the current Widdecombe roadshow, in which she tours the country under the rubric of "A Night with Ann Widdecombe", talking about politics, her novels (a third, Father Figures, will come out at the end of this year) or anything else. "I am convinced that this is the phoenix rising out of the ashes of the old public meeting. This is people wanting to see what their politicians are like."

She would "never in 20 million years" do Celebrity Big Brother ("vulgar and voyeuristic in the extreme"), and always insists on only doing what she wants to do.

Was her success on Celebrity Fit Club and the Louis Theroux one before it, in which she emerged as a "personality" rather than a scary ideologue, building a base for a return to frontbench politics?

"I just don't bother thinking about it. Almighty God knows what he wants me to do over the next five years. Doubtless he will demonstrate this to me at some point."