According to various press reports party leader Iain Duncan Smith has lost confidence in Mrs May.

There is no merit in retreating into a bunker mentality and mouthing mantras for core voters John Bercow

But a Conservative Party spokesman told BBC News Online there was nothing in the reports.

The reported plan comes hot on the heels of the departure of key aides widely associated with the reforming wing of the Conservatives.

It also coincides with rumours that Mr Duncan Smith is planning some fairly substantial changes in his frontbench team later this year.

However Tory party officials say Mrs May was fully involved in those decisions and knew what was going on.

Need to change

Mrs May is famed for her rather racy taste in shoes and for being the Conservatives' first woman chairman.

She also hit the headlines at the party conference last year when she told fellow Tories they had to lose their "nasty, narrow" image or face further electoral disaster.

Will the Tory leader keep his chairman?

Chief executive Mark MacGregor resigned from Conservative Central Office last week to become director of Steve Norris's campaign for London mayor.

That prompted Tory MP John Bercow to say that he feared arch-moderniser Mr MacGregor's decision to go could mean the abandonment of a more forward looking approach to politics.

Mr MacGregor, who has reportedly clashed with Mr Duncan Smith, is widely credited for the party's strategy to help the vulnerable, improve public services, the plight of the poor and victims of domestic violence.

The appointment of former Tory MP Barry Legg as chief executive and chief of staff will be viewed by some observers as a victory for those hoping Mr Duncan Smith will take on a more traditional right-wing approach to politics.

'Badly missed'

John Bercow, who quit the Conservative front bench over the party's opposition to allowing unmarried couples - heterosexual and gay - to adopt children, said it was a "great pity" to see Mr MacGregor go.

"I am very disappointed. Mark MacGregor is certainly one of the most talented people in Conservative politics that I have ever met and his talents will be badly missed at Central Office," he told BBC Radio 4's Today programme.

"He ran an excellent Conservative conference, focusing on public services, on helping the vulnerable and indeed on updating the Tory outlook to reflect modern Britain.

"I have felt that in recent months his voice has been drowned out and that since the conference, the modernising agenda has been at best, sidelined and at worst, lost."

Asked if Mr MacGregor's decision to quit was associated with his keen support for former leadership challenger Michael Portillo, Mr Bercow insisted: "No, I don't accept that at all.

"Mark's one of the most loyal people I have ever met - I've known him for 20 years.

"He transferred his allegiance when Michael Portillo was defeated, to Iain Duncan Smith."

He added: "If ... new appointments are made of people who, at least on the face of it, appear not to subscribe to a modern, positive and forward looking agenda, then people will start to say ... what has happened?

'Bunker mentality'

"Have you dropped or down graded the modernising strategy and opted, instead, for a reversion to the core vote strategy?

"I hope not because that is exactly what happened at this stage in the last Parliament. It didn't work then and it isn't working now."

Mr Bercow said he was "certainly very worried" that Mr Duncan Smith had gone back on his modernising agenda.

"There is no merit in retreating into a bunker mentality and mouthing mantras for core voters, which might well appeal to them and to our party workers, but simply don't have any resonance beyond that category," said Mr Bercow.