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Boris Johnson will vow to "support women to reach their full potential" in politics and the workplace if the Conservatives win the general election.

He will also announce the "biggest drive" to recruit female Tory activists, members and candidates.

On the 100th anniversary of the election of the first woman to sit in the Commons, the PM will pledge to make 50% of future Tory candidates women.

In this election 30% of Tory candidates and 53% of Labour candidates are women.

Labour has hit back by criticising the prime minister's attitude towards women, highlighting "sexist" remarks he has made in the past.

The party says in articles written for The Spectator magazine, Mr Johnson made disparaging comments about single mothers and unmarried women.

They say this shows his attitude is "straight out of the dark ages".

Mr Johnson's announcement comes as a statue of Nancy Astor - the first woman MP to take a seat in Parliament, 100 years ago - is due to be unveiled in Plymouth.

Commenting on her career, Mr Johnson said: "She was a trailblazer, ripping up the conventions that held women back from joining the workplace.

"A Conservative majority government will support women to reach their full potential - be that in the workplace, by opening up new opportunities to work flexibly or start their own business, or through our work internationally to make sure all young women get 12 years of education."

Mrs Astor was elected to represent Plymouth for the Conservative Party, the year after women over 30 who met a property qualification were given the vote.

Constance Markievticz was the first woman to be elected to Parliament in 1918, but her membership of the Irish republican party Sinn Féin stopped her from taking the oath, meaning she could not sit in the Commons.

Image copyright Getty Images Image caption Nancy Astor became the first female MP in Westminster in 1919

Women make up about a third of candidates in next month's election. According to BBC analysis of Press Association figures earlier this month, 1,124 of 3,322 registered candidates are women.

The Tories say they have 193 female Conservative parliamentary candidates, while Labour has 335.

Mr Johnson said: "I have often said that talent and brilliance is equally distributed, but opportunity is not. I will make sure that women are supported to take up the opportunities that politics present."

The Conservatives say they want to encourage flexible working, review how to better support self-employed workers and protect women returning from maternity leave by reforming redundancy law.

But the Labour Party highlighted "sexist and misogynistic" comments made by Mr Johnson in articles written in the 1990s.

Labour's shadow attorney general Shami Chakrabarti said: "Someone whose attitudes towards women are straight out of the dark ages is not fit to be prime minister of our country."

In September it emerged that Mr Johnson wrote that David Cameron was a "girly swot" on a private cabinet paper.

And days earlier Mr Johnson was criticised for calling Jeremy Corbyn a "big girl's blouse" over the Labour leader's decision not to back the prime minister's bid for an election while the risk of a no-deal Brexit remained.