If there’s one Conservative MP who sums up an entire political era, it’s Michael Portillo.

Jeffrey Archer and Jonathan Aitken aside, there was something about him – the smile that didn’t quite reach his eyes, his refusal to answer direct questions, the endless rumours that circulated about his private life and his crucifyingly public defeat in 1997.

Yet he walked away from all this with a media career and fascinating projects, from political commentating to social documentaries. Which is why his ‘evening with’ show sells out wherever he goes.

Pitching up in Didcot on Sunday, Michael has got a lot to talk about. After all, he went on to hold several of the great offices of state. As the infamous Conservative MP for Enfield Southgate, he was a member of the government from 1986-1997 as Minister of State for Transport, Chief Secretary to the Treasury, Secretary of State for Employment and Secretary of State for Defence, and then became Shadow Chancellor of the Exchequer.

Now a panellist on Radio 4’s The Moral Maze and, for the past four years, a regular alongside the Labour MP Diane Abbott and Andrew Neil on BBC1’s political discussion programme This Week, the 54-year-old somehow also finds the time to write a weekly column for The Sunday Times.

While Michael consistently refuses to write an autobiography, he’s happy to tell you all about his life on stage.

“I relish the contact with people,” he explains. “I always enjoyed that when I was in politics and these days there are fewer opportunities for it. These are really very enjoyable and stimulating occasions. I particularly enjoy the Q&As when the questions can be unexpected, penetrative, amusing or off the wall – it’s a live and unpredictable event.

“And the great thing about not being in politics is that you’re much more in control of how you’re perceived,” he muses. “People come up to me and say, ‘you’re much nicer now you’re not a Minister,’ but it’s all about context. When you’re in the dock being questioned on Newsnight by Jeremy Paxman – whose attitude is ‘why is this bloody liar bloody lying to me?’ – then it’s hard to appear relaxed. It’s much easier work making a documentary!”

So what changed? “The genius of Tony Blair, Bill Clinton and David Cameron is that when under immense pressure, they remain friendly and smiley. I couldn’t manage that, and some people thought my manner was arrogant. But I find it very difficult to control my face, and maybe it showed that I was terrified when under pressure. Either way, my life is a lot easier now!”

People also hark back to the famous footage of him losing his seat at the 1997 General Election, an iconic moment of New Labour’s landslide victory.

But instead of defending himself Michael says: “People will find it hard to believe, but I was actually relieved.

“We lost so catastrophically that there was no prospect of winning the next election.

“Although,” he adds with a self-deprecating peal of laughter, “I was quite frustrated when it was voted Channel 4’s third most enjoyable TV moment of the 20th Century!”

And he didn’t mope about bemoaning his fate.

“One had to do something about reinventing oneself,” he reflects. “I did get hurt at the time, but I was quickly up and running. I lost my seat in May, and by June I was already making a documentary.”

He is equally philosophical about his failure to become Tory leader. “I don’t regret the fact that I never became leader. Whenever it was in prospect, it was not very inviting. It would have been such a struggle against an unwilling party.”

Instead, Michael seems to have found his niche on TV.

“I love working on documentaries. They are very absorbing intellectually and they produce a wonderful team spirit. I feel privileged to have made films about my father, music, travel and wildlife,” he says.

One documentary that stands out is When Michael Portillo Became A Single Mum. “I’m very, very pleased I made that one,” he beams. “I had to live like a single mum and run a family on just £80 a week, and people could tell the whole thing was genuine. I knew which highlights would be included. I knew full well that the moment where I had to scrape an egg off the floor and put it back in the pan would make it to the finished film, but I just couldn’t afford to lose an egg!”

The other programme that viewers adore is This Week. “It’s really struck a chord with people,” Michael enthuses. “We were taken on for 12 weeks in 2003 and now we’ve done it for 4.5 years! Viewers appear to like the relationship between Diane and me. Diane and I were at school together, so we have a shared history. But people can’t predict what we’re going to say.” Maybe that’s his secret.