Samantha Cameron makes a disigner decision for David big moment

Stylish Samantha dress £750 black silk designer dress from Paul Smith's autumn 2010 range

Last year Samantha Cameron made headlines when she chose a £65 Marks & Spencer dress for her husband's party conference.

Fast forward 12 months and the mum-of-three is now the prime minister's wife – and she has the wardrobe to match.

Samantha dressed to impress at David's first party conference as PM this week. She chose a £750 black silk designer dress from Paul Smith's autumn 2010 range.

Showing off an incredible post-baby figure less than two months after giving birth, the 39-year-old threatened to steal the show in the frock, which featured a pretty pink water rose print.

And just like Justine Thornton – Labout leader Ed Miliband's long-term partner – Samantha chose a pair of black heels from LK Bennett to complete the outfit.

Her look was evidently a big hit with her husband.