Samantha Cameron, Carla Bruni and Michelle Obama have all been voted onto the style elite of Vanity Fair’s 2010 International Best Dressed List.

The eight-month pregnant UK prime minister’s wife joins regulars Bruni and Obama along with other notable UK style icons David Beckham and Lady Gaga. According to Vanity Fair, Mrs Cameron is the ‘UK First Lady’, and wears the ‘realpolitik’ look. The magazine also lists Mrs Cameron as employed by upmarket stationers Smythson as a creative director.

In a comprehensive detail of the PM’s wife, Vanity Fair says Mrs Cameron, 39, is often seen in numbers from Erdem and Phillip Lam, accompanied by bib necklaces, brooches and chain pendants. When it comes to dressing down, Mrs Cameron can be seen sporting a pair of sneakers and more often than not, a pram. Tickets for Troops, the returned services organisation set up by the Tories last year, is listed as her favourite cause. Mrs Cameron is known to have close ties in the fashion industry, with her sister being deputy editor at British Vogue.

Aside from her fabled dolphin ankle-tattoo, Mrs Cameron is best known for sporting a £65 grey polka dot dress from high street retailers Marks and Spencer to augment the austerity theme of last year’s Conservative Party conference.

The Vanity Fair list, which has been one of the key indexes for fashion heavyweights for the past 71 years, also featured Princess Mary of Denmark, Helena Bonham Carter, John Galliano, Martin Scorcese, Alec Baldwin and Javier Badem.

The incumbent British Prime Minister, Gordon Brown, has announced that he will be resigning from his post by September at the latest.

While Mr Brown and his fellow Labour Party ministers are working around the clock to try and reach an agreement with the Liberal Democrats on forming a new government, any such eventuality will not be headed by the current Labour leader who hopes to hang on to the reigns until the next party conference.

The presence of Mr Brown at number 10 Downing Street has widely been regarded as detrimental to his party’s chances of making a new deal with Nick Clegg. The announcement has therefore not been as much of a surprise as it may have seemed, with the focus on both sides firmly on finding common ground on the issue of electoral reform.

Both the poll-leading Conservative Party and Mr Brown’s Labour Party have been trying to woo the liberal Democrats through a range of reform initiatives as the battle for Britain’s leadership enters a critical phase.

The Tories responded to Mr Brown’s resignation announcement by offering the Liberal Democrats one final chance to introduce a referendum of Britain’s voting method, with the latter favouring a move to the Alternative Vote (AV) system.  Labour has gone further, offering to make the AV system law before conducting a referendum seeking voter approval.

Tomorrow is looming as crunch time for all concerned, with a full Liberal Democrat coalition with one or other of the main parties the most likely outcome.