Michael Portillo has admitted that the modernising wing of the Conservative Party faces defeat.

With Michael Howard expected to be elected unopposed as Tory leader on Thursday, Portillo warned that the party was likely to remain socially conservative.

"The 'modernisers' do not expect much movement in their direction from Michael Howard," he wrote in Sunday's Observer newspaper.

"He doesn't see the point in shifting the party on issues such as adoption by gay couples, though presumably [Iain] Duncan Smith's grim experiences will suggest that he should avoid three-line whips on social issues."

But the former defence secretary urged Howard not to ignore the case the Tory left was making for change.

"The modernisers in the party are a minority so he has no obligation particularly to listen to what we are saying," he added on BBC1's Breakfast with Frost.

"But I do think that the Conservative Party has a problem, particularly with its representation.

"There are too many people like me - white, middle-aged, from the south-east of England, middle class, and we do want some more variety in the party.

"We need to look as though we represent society as a whole and that we understand society as it is.

"I don't think Michael is as signed up to all that as perhaps I am, but on the other hand he is now leader and I am sure he will want to consider all the issues and the points of view that are put forward."

Portillo also welcomed the fact that his former Cabinet colleague was set to crowned without a divisive leadership election.

"Very few had dared even to hope that the leader's demise could be followed by consensus regarding his successor," he wrote.

"By Thursday, we realised that the nightmare of another long leadership election had been just a dream after all."

And Howard's predecessor as shadow chancellor, now MP for Kensington and Chelsea, refused to rule out a possible return to the frontbench.