Glenda Jackson, Oscar-winning actress, former British MP, dead at 87

June 15 (UPI) -- Oscar-winning actress and former Labor Member of Parliament Glenda Jackson died Thursday, according to her agent. She was 87 years old.

Jackson's agent Lionel Larner said in a statement that she "died peacefully at her home in Blackheath, London this morning after a brief illness with her family at her side."

She had recently completed filming for The Great Escaper in which she starred alongside Michael Cain. The upcoming film tells the true story of a British veteran who escaped a care home to attend the 70th anniversary of the D-Day landings in France's Normandie region.

"Today we lost one of the world's greatest actresses and I have lost a best friend of over 50 years," Larner said.

Jackson appeared on stage for the Royal Shakespeare Company in the 1960s where she played roles in Hamlet and Antony and Cleopatra.

She won a Best Actress Oscar in 1970 for the film Women in Love, based on the novel by D.H. Lawrence. In 1973, she won an Oscar for her role in the film A Touch of Class.

Jackson did not attend the ceremonies for either of her Oscar wins. She also won an Emmy and a Tony Award during her career.

Jackson was a critic of Margaret Thatcher's conservative government, and in 1992, during John Major's tenure as prime minister, she was elected MP for Hampstead and Highgate.

After winning her seat, Jackson said "we must work for the poor, the homeless, the unemployed, the frail, the sick."

When Tony Blair started his New Labor project, which sought to bring the party to a more centrist position, Jackson was part of the Labor contingent that opposed the move away from more traditional Labor positions.

"Very sad to hear of the death of Glenda Jackson. I served alongside her in Parliament for many years. She was a kind and extremely principled woman," Labor MP for Hackney, Diane Abbott, tweeted Thursday.

Abbott, who became the first Black woman elected to Britain's Parliament in 1987, was a close associate of Jackson.

Downing Street said British Prime Minster Rishi Sunak's "thoughts will be with her friends and family at this time."

Jackon left her seat in 2015 and returned to acting, portraying a woman struggling with dementia in Elizabeth is Missing. The performance earned Jackson a BAFTA award for Best Actress.

She is survived by her son Daniel.