Theresa May has spoken of her delight at being named the Conservative Party's first woman chairman in Iain Duncan Smith's shadow cabinet reshuffle.

Mrs May, who was shadow transport secretary, said she believed her appointment was symbolic of the way the party had changed.

Tory changes

Party chairman Theresa May Tim Collins becomes transport spokesman Tim Yeo gets trade and industry John Whittingdale becomes culture spokesman John Bercow moves to pensions Howard Flight shadows the chief secretary to the Treasury Former chairman David Davis shadows John Prescott in the Commons John Hayes moves to rural affairs

She takes over from David Davis who has been moved to a newly created position, shadowing Deputy Prime Minister John Prescott.

Mr Duncan Smith said it had been his duty as leader to make decisions "about who I think are the round pegs in the round holes".

Other changes see John Bercow moved from his post shadowing the chief secretary to the Treasury to take on pension matters.

Former culture spokesman Tim Yeo moves to trade and industry while former trade spokesman John Whittingdale gets Mr Yeo's old job.

At a press conference, Mrs May, 45, said: "I believe the Conservative Party has changed and my appointment as the first woman chairman symbolises that change.

"Now my job is to take that message out across the country at large under our campaign to help the vulnerable.

"The Conservative Party is an open, decent and tolerant party. We are committed to reform of public services...

"Our job is to oppose a government that is taking more and more of people's money, but is delivering poor public services. We can show that there is a better way for Britain."

'Very happy'

Mr Duncan Smith said he and Mr Davis had "spoken at length" about the former chairman's new role.

"David has been very happy to take the job I offered him which was shadowing the office of the deputy prime minister."

Davis: Accused of blocking modernisation

The Tory leader insisted: "That is a big job because it brings in a lot of the Cabinet Office areas as well as local government areas and the regions."

Mr Davis would be working with Tory shadow transport minister Eric Pickles as the government beefs up its regional government agenda, he said.

Asked if Mr Davis had been an unsuccessful chairman, Mr Duncan Smith retorted: "We now need to change the emphasis."

He added: "It's my duty as leader - I'm in charge, I must make these decisions about who I think are the round pegs in the round holes."

'Meteoric rise'

Mr Duncan Smith said Mrs May was the "best" person to coordinate and focus the party.

Mrs May has had a "meteoric" rise through the party's ranks since becoming MP for Maidenhead in 1997.

Mr Duncan Smith was particularly impressed by her persistent calls for Stephen Byers to quit as Transport Secretary during the spin debacle, party officials said.

Mr Duncan Smith refused to speculate on the reshuffle

Mrs May is said to personify the changes Mr Duncan Smith intends to make to the party, with greater inclusiveness and accessibility to ethnic minorities and women high on the agenda.

Reports claim the reshuffle follows divisions between the Tory leader and Mr Davis, who some colleagues have accused of blocking efforts to modernise the party.

'No rift'

But deputy Tory leader Michael Ancram told BBC Radio 4's World at One programme: "In the run up to reshuffles there are alwys leaks and stories in newspapers.

He denied that Mr Davis had "committed a crime".

"Shadowing the deputy prime minister is hardly a demotion - it's a very important job and I am sure he will do it very well."

Mr Davis has surprised some at Westminster by taking a summer holiday in Florida while the House of Commons is still sitting.

Some newspaper reports quoted unnamed Tory sources as saying Mr Davis had lost favour because he had failed to drive through reforms to ensure the party had greater numbers of women and ethnic minority candidates.

It was also suggested that Mr Davis was keeping his distance from Mr Duncan Smith's team as he prepared to run for the leadership again.

Lib Dem parliamentary party chairman Mark Oaten MP said: "This reshuffle is a sign of a Leader desperate to cover up his own inadequacies by scapegoating the party chairman.

"What will Mr Duncan Smith do if the Tories are still on 30% in the polls a year from now?"

Labour Party chairman Charles Clarke said: "I think it's the first time in recent recorded political history that the leading conspirator has been promoted to prosecute his conspiracy more energetically."

"I think it's a very surprising move."