William Hague and Michael Portillo have pushed Conservative leadership woes into the limelight.

Advice from Iain Duncan Smith's predecessor and a thinly veiled warning from a rival have blown apart Central Office's denials of a crisis.

Portillo called on Duncan Smith to fight for his job. And speaking to Channel 5 news, he refused to say whether the beleaguered Conservative leader would survive until the next general election.

"I don't want to kid you. There have been mutterings and think Iain Duncan Smith has to fight back. The position is perfectly retrievable. But he has got to fight. He has got to show he wants the leadership," said the Kensington and Chelsea MP.

In a Times article, Hague appeals to backbench Conservative MPs to give Duncan Smith a chance.

"I know of no other leader of the Conservative Party who would not have to face the same difficulties," he writes.

"I hope the rumours I read of plots against my successor are soon forgotten."

The newspaper reports that up to 30 local Conservative associations have criticised the leadership.

It also claims that MPs are suggesting that Estelle Morris has "shown Iain the way" by resigning because she was not up to the job.

The Tory blues drowned out a successful prime minister's question time for Duncan Smith, who later toured the Commons tea room to bolster support.

The Telegraph talks to the Tory leader's "close associates", who name his four most persistent backbench critics: Totnes MP Anthony Steen; Bracknell MP Andrew Mackay; former agriculture secretary Douglas Hogg; and Andrew Mitchell.

Another Central Office ally of Duncan Smith tells the newspaper that the MPs should "shut up" or face trouble in their constituencies.

Duncan Smith also faces plots of another political complexion.

A leaked letter from the Labour MP Tom Watson to the new party chairman, John Reid, says: "Iain Duncan Smith's survival through to the next election would clearly be beneficial to us."

"Yet some colleagues have been so successful at turning him into a laughing stock that confidence is rapidly draining away on his own side," warns the West Bromwich MP.