Newly-elected Tory leader Iain Duncan Smith moved swiftly to stamp his authority on his party last night, installing key supporters to his Shadow Cabinet.

After appointing one-time rival candidate David Davis as party chairman, Mr Duncan Smith appointed another participant in the leadership race, former party chairman Michael Ancram, as Shadow Foreign Secretary.

Former Home Secretary Michael Howard was installed as his Shadow Chancellor.

Mr Duncan Smith appointed his campaign manager Bernard Jenkin as Shadow Defence Secretary.

Controversial former economics spokesman Oliver Letwin got the post of Shadow Home Secretary, and former defence spokesman Quentin Davies was installed as Shadow Northern Ireland Secretary.

Earlier, Mr Duncan Smith succeeded William Hague as party leader, easily beating off rival Kenneth Clarke.

Mr Duncan Smith polled 155,933 votes to Mr Clarke's 100,864, a 61 per cent to 39 per cent share of the vote on a 79 per cent turnout of 256,797 Tory members.

A Conservative spokes-man said later the result was a "ringing endorsement" of Mr Duncan Smith.

The result, and Mr Duncan Smith's Shadow Cabinet plans, were interpreted by his supporters as an endorsement, too, of his strong Eurosceptic views.

Though he was happy to accept Mr Clarke's congratulations earlier in the day, there was little sign in his early appointments that he is concerned about extending an olive branch to the Left of the party.

He also demonstrated an awareness of the need to reward key figures who gave his campaign a boost at vital junctures.

Mr Ancram had been expected - following his own ejection from the leadership contest - to back Mr Clarke.

But his decision to support Mr Duncan Smith earned him the reward of the key post of Shadow Foreign Secretary.

David Davis's leadership campaign won more support than many had expected, and by giving him the chairmanship role, Mr Duncan Smith ensured that a potential future rival is closely tied to the success of his own leadership.

Party sources described Mr Davis, the MP for Haltemprice and Howden, East Yorkshire, as "a street fighter who will take the battle to Labour".

Mr Davis is also understood to have been given a key role in policy development as the Tories struggle to overhaul Labour's massive Commons majority