Tiara belonging to first female MP to take seat expected to fetch £250,000

A Cartier turquoise and diamond tiara owned by the first woman to take a seat in the House of Commons is expected to fetch more than £250,000 at auction.

American-born Nancy Astor was elected in 1919 to represent Plymouth Sutton in Parliament and held the seat until she stood down in 1945.

London Auctioneers Bonhams said the auction in June would see the tiara on the market for the first time since it was bought by her husband Lord Waldorf Astor in 1930.

Global head of jewellery at Bonhams Jean Ghika said the "exceptionally rare" tiara with "impeccable provenance" dates from when Cartier London was at the "height of its creative prowess".

The tiara features single, rose-cut and brilliant-cut diamonds and three fluted turquoise plumes set with diamond stems, according to Bonhams.

The auction house said it was worn by Lady Astor to the film premiere of City Lights at the Dominion Theatre in London in 1931.

Bonhams estimates the tiara could sell for between £250,000 and £350,000.

Ms Ghika said: "With impeccable provenance and a compelling marriage of Western and Eastern influences in the design, the tiara is exceptionally rare."

She added that the auction house felt "honoured to have the opportunity to present it for sale for the first time in nearly a century".

Nancy Astor was born Nancy Witcher Langhorne in Danville, Virginia, in 1879.

In 1905 she moved to England and met the American-born Waldorf Astor, 2nd Viscount Astor, on the same voyage across the Atlantic from America.

The couple were married in 1906 and after Lord Astor relinquished his seat in the House of Commons in 1919, Nancy Astor was elected by substantial majority in his place.

During her time in government she pushed for the Intoxicating Liquor Act, known as Lady Astor's Bill, which passed in 1923, raising the legal drinking age from 14 to 18.

She also argued for the rights of women and successfully saw the female voting age lowered from 30 to 21 in 1928.

She was successfully re-elected seven times during her 26 years in the House of Commons and retired in 1945.

Campaigners have accused Lady Astor of being anti-Semitic, anti-Catholic and a Nazi sympathiser but supporters say she was a victim of misogyny and was "opposed to Nazism".

She died in Lincolnshire in 1964 at the age of 84.

The auction is due to take place at Bonhams in New Bond Street, London, on 5 June.