The former Secretary of State for Defence, who lost his Enfield Southgate seat at the 1997 election, is ready to risk another humiliating defeat in order to get back to Westminster.
"I am assuming I will go back," he told the Independent on Sunday. "I would certainly look at a by-election if one comes up. All by-elections are a risk - you are never sure of winning."
Although Mr Portillo stressed that he had not yet finally taken the decision to stand, his friends say it is now almost certain that he would put his name forward for the next by-election that comes up, if he had a "reasonable" chance of getting through it.
The former MP, whose surprise defeat last May came to symbolise the rout of the Conservatives, is determined to help revive the party's fortunes. He is planning to make two major speeches at the conference in Bournemouth next month and his television series on the Conservatives, Portillo's Progress, starts tonight on Channel Four at 8pm.
He also believes that he could have a useful role in the House of Commons. "I think there might be more to do," he said. "I think I could play a part and I think I would probably enjoy it - although all these things are a bit tentative."
Mr Portillo's determination to return to Westminster will raise the prospect that he could become a challenger to William Hague. But he dismissed the idea as "preposterous" and said he was fully behind the Tory leader. "I supported him in the leadership election and I support him still," he said.
In the eyes of the British public, Mr Portillo would be returning to the Commons a different man. Before election night he somehow epitomised everything people hated about the Tories - he was perceived as smug, arrogant and out of touch. But as his quiff wilted with the Conservative majority, he won respect in surprising places.
Even Labour MPs now admit a sneaking admiration for the dignity he showed through his speech about the "truly terrible night" his party had had. In fact Mr Portillo has developed such a rapport with Peter Mandelson that he recently invited him to dinner at his Victoria home.
Mr Portillo agrees that the night of 1 May improved his image more effectively than anything he could have done as an MP. "An event with millions watching probably had more of an effect on shaping people's view of me than anything else that could have happened," he said, "although the circumstances were hardly planned."
There is no doubt that Mr Portillo has softened. Where once he read military briefing papers and listened to Wagner, now he savours Proust and the romantic writer Alain de Botton. The ministerial car has been replaced with the Number 73 bus and the pin-striped suits thrown out in favour of button-down shirts. In his television series he is portrayed punting in Cambridge, leaning against a farm gate on the Yorkshire moors and watching single mothers change nappies on council estates.
The political makeover began at the Tory conference last year when he "came out" as a "compassionate Conservative" who would tolerate lone parents. The speech was "certainly deliberate" he says, although he was astonished by the reaction it generated. "I wrote it with a sense of relief because I thought 'I can now say exactly what I think about these issues'." He says he finds it liberating to be able to speak his mind as a political outsider.
He identifies the Tories' main failure before the election in a way he never could have done had he stayed on the front bench: "They didn't really know what they stood for or what they thought." Making the television series showed him how hated the Conservatives still are.
His next television project, for the BBC, is more personal. He is tracing his family history through a train journey across Spain. It was, he says, a "completely absorbing, moving" experience. He speaks to relatives who fought on different sides in the Spanish civil war. "It was emotional reliving the stories of my father's life - he was a republican, on the losing side, he had to leave the country and was unable to go back for 20 years. My uncle Victor says my father was an idealist who didn't have his feet on the ground."
In the past, Mr Portillo's critics would have said the same about him. Now they cannot be so sure.Reuse content