Smith is first female Home Secretary

Prime Minister Gordon Brown made the announcement as he unveiled his first Cabinet yesterday.

Mrs Smith, 44, MP for Redditch, first entered Parliament in 1997 when Tony Blair swept to power with New Labour.

She was previously chief whip, working with Worcester MP Mike Foster and 15 other whips.

She said: "I am immensely proud to be asked by Gordon Brown to take on this role. It's hard to imagine a greater responsibility for someone elected by the British people than to be tasked with the job of protecting our borders, communities and people in order that they can get on with their lives. I am very proud of being appointed and I am now going to get on with it."

Mr Foster congratulated his colleague by saying: "We've known each other for over 20 years and I used to live by her in Redditch in the mid 80s and early 90s.

"I was her agent when she stood in the 1992 general election, we've been on family holidays together, and I'm absolutely delighed for her - she's incredibly capable."

Mr Foster was due to find out if he has kept his job as a whip today.

As part of the cabinet reshuffle, rising star David Miliband was given the plum job of Foreign Secretary. Mr Miliband, 41, becomes the youngest MP to hold the role since David Owen in 1977.

His appointment to succeed Margaret Beckett will inevitably be seen as reward for resisting temptation to stand against Mr Brown as a Blairite leadership candidate.

Alan Johnson will be the new Health Secretary, switching from education, as the Prime Minister puts the finishing touches to his new administration.

Peter Hain is expected to be named as Work and Pensions Secretary, James Purnell as Culture Secretary and Hilary Benn is switching from Department for International Development to Environment replacing Mr Miliband.

The Department of Trade and Industry is to be renamed the Department for Business and Enterprise. John Hutton is moving from work and pensions to be the new minister heading the department.