Personal items belonging to Britain's "Iron Lady" prime minister Margaret Thatcher, including some of her famous handbags, are to be sold in London next month, Christie's auction house said Tuesday.

Around 350 lots including clothes and jewellery accrued during her 87 years -- 11 of which were spent in Downing Street -- are being sold after the Victoria & Albert Museum turned them down.

An emerald and diamond Chaumet necklace, valued between £120,000 ($185,000, 168,000 euros) and £180,000, is expected to fetch the highest price, with proceeds to be split between Thatcher's children Mark and Carol, and her grandchildren.

"In the year that 'The Iron Lady' would have celebrated her 90th birthday, approximately 350 historic and personal lots will be offered across two landmark sales," said Christie's.

"These sales are taking place 25 years after Margaret Thatcher left office, at the end of her 11-year high-profile tenure as prime minister.

"These auctions present unique opportunities, across price levels, for collectors around the world to acquire property from the longest-serving prime minister of the United Kingdom in the 20th century and the only woman to have held office to date," it added.

The items were initially offered to The Victoria & Albert Museum in London, the world's largest museum of decorative arts and design, but they decided against showing the objects.

"The V&A politely declined the offer of Baroness Thatcher's clothes, feeling that these records of Britain's political history were best suited to another collection which would focus on their intrinsic social historical value," said the museum.

"The museum is responsible for chronicling fashionable dress and its collecting policy tends to focus on acquiring examples of outstanding aesthetic or technical quality."

Thatcher's programme of privatisations and deregulation helped turn around Britain's ailing economy following her election in 1979, and she is also credited with playing a leading role in ending the Cold War.

But she remains a divisive figure, particularly in Britain's working-class heartlands, which suffered devastating industrial decline as a result of the economic rebalancing.

She died on April 8, 2013, and received a ceremonial funeral, including full military honours, attended by Queen Elizabeth II.

The auction will take place on December 15, and an online-only sale comprising 200 lots will run for two weeks from December 3. It is expected to raise around £500,000.

Thatcher's most famous handbag, which struck fear into the hearts of British ministers during the former premier's rule, sold at a charity auction for £25,000 in 2011.