Media playback is unsupported on your device Media caption The Daily Politics looked at some of the highlights of Harriet Harman's career in 2015

Labour's Harriet Harman has become the longest continuously serving female MP, racking up 12,468 days in the Commons.

Since Ms Harman was elected in a Peckham by-election in 1982, she has worked with seven different Labour leaders and been acting leader twice.

Friday marks the day she surpasses Gwyneth Dunwoody's record, although the late Labour MP served longer overall in two separate periods.

The longest-serving MP is Sir Gerald Kaufman who was first elected in 1970.

Image copyright Getty Images Image caption Ms Harman was elected as Labour's deputy leader in 2007 - but was not made deputy PM

Image caption Ms Harman is a long standing campaigner for women's rights

Image copyright Getty Images Image caption Ms Harman's pink bus attracted mixed responses on the 2015 general election campaign trail

Sacked as social security secretary from Tony Blair's first cabinet, Ms Harman returned to the front bench as solicitor general in 2001 and served in various roles including Commons leader and equalities secretary under Gordon Brown.

Ms Harman has served as Labour's deputy leader, under Gordon Brown's premiership, and as acting leader after Mr Brown stepped down following the 2010 general election and in 2015, when his successor Ed Miliband quit.

She has long campaigned for more women MPs and more family-friendly policies and has sometimes been dubbed "Labour's in-house feminist", but she has also criticised the number of men in top jobs in the party.

And it has been a source of embarrassment to Labour that they have never had a female leader - while the Conservatives have had two.

In a speech in Westminster in 2014, Ms Harman admitted she was "surprised" by Mr Brown's decision not to make her deputy prime minister - as deputy leader John Prescott had been under Tony Blair, saying: "If one of the men had won the deputy leadership would that have happened? "Would they have put up with it? I doubt it."

Among those congratulating her on Friday was her Labour colleague in the neighbouring London constituency of Dulwich and West Norwood, Helen Hayes, who tweeted: "Thank you for the huge difference you have made, esp for women." Ms Harman thanked her adding: "Much done but so much to do."

Mrs Dunwoody, who was 77 when she died in 2008, served for more years overall, having been first elected in 1966 as MP for Exeter. She lost the seat in 1970 but was elected as MP for Crewe in 1974 and remained in the Commons until her death.