The seven suits, all of which were worn by the 'Iron Lady' in the early part of her career, are thought to be the first of Lady Thatcher's clothes to be sold at a public auction, BBC News reported.
The outfits are being sold by a private collector at Christie's as part of its "London Sale", a one-off themed auction being held to celebrate the Queen's Diamond Jubilee and London 2012.
All of Lady Thatcher's outfits have been given a guide price of between 1,000 pounds and 1,500 pounds.
Pat Frost, Head of the Textiles Department at Christie's described the sale as a "one-off opportunity", adding she was not aware of any clothing items of Margaret Thatcher's being sold at a public auction before.
Unlike other known political figures such as Sir Winston Churchill, she said, it was impossible to tell how popular the items would be.
"These outfits were worn at the beginning of her career, when she got the 'milk snatcher' tag, and were part of important moments like her introduction as leader at the Conservative Party conference," she told the BBC.
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The outfits on sale include the light green suit worn by Lady Thatcher the day she was confirmed as the new leader of the Conservative Party and the striking yellow dress with navy trim at her first party conference as leader in 1975.
Other suits were worn when she was an education minister during television or radio appearances.
Last year, a handbag carried by her when meeting US President Ronald Reagan had raised 25,000 pounds at a charity auction.