Theresa May has said she will not fight the next general election, bringing a 27-year career in Parliament to an end.

The former prime minister revealed her decision to stand down as MP for Maidenhead on Friday, saying she would focus on championing causes including the fight against modern slavery.

In a statement to her local newspaper, the Maidenhead Advertiser, she said: “Since stepping down as prime minister I have enjoyed being a backbencher again and having more time to work for my constituents and champion causes close to my heart including most recently launching a Global Commission on Modern Slavery and Human Trafficking.

“These causes have been taking an increasing amount of my time.

“Because of this, after much careful thought and consideration, I have realised that, looking ahead, I would no longer be able to do my job as an MP in the way I believe is right and my constituents deserve.”

Mrs May, 67, has been a consistent campaigner on modern slavery and human trafficking, and launched her Global Commission in October, backed by the UK and Bahrain governments.

She was first elected as MP for Maidenhead in 1997, and served as home secretary under David Cameron between 2010 and 2016 before succeeding him as prime minister.

Her term in Downing Street lasted a turbulent three years and was dominated by wrangling over Brexit. A snap election in 2017 saw her lose her majority, but she remained at Number 10 thanks to a deal with the DUP in the resulting hung parliament.

Eventually, opposition to her proposed Brexit deal saw Conservative MPs hold a confidence vote in her leadership, and although she survived her authority was diminished and she announced her resignation five months later.

In her statement, Mrs May said it had been “an honour and a privilege” to serve as Maidenhead’s MP and vowed to continue working for her constituents until the general election, which is expected in the second half of this year.

She added: “As I pass the baton on I will be working with my successor to secure a Conservative victory in Maidenhead. I remain committed to supporting Rishi Sunak and the Government and believe that the Conservatives can win the election.

“I would like to thank all those who chose me to represent them as their Member of Parliament.”

The Prime Minister paid tribute to Mrs May, describing her as “a relentless campaigner” and “a fiercely loyal MP to the people of Maidenhead” who “defines what it means to be a public servant”.

Speaking to reporters in the West Yorkshire town of Keighley, he said: “Obviously on International Women’s Day, it’s important to recognise that Theresa was our second female prime minister, which is an extraordinary achievement.

“And actually beyond that, she just has the most amazing track record of dedicated public service over two decades. And that is an extraordinary and inspiring example to anyone.

“Anyone who spent time with her knows how committed she is to public service, not just in her community, but the country. And everyone will miss her sorely.”

Almost 100 MPs have now announced they will not fight their seats at the next election, including 64 Conservatives and former Conservatives – the most Tories to retire from Parliament since Mrs May entered the Commons in 1997.

Labour Party chairwoman Anneliese Dodds said the number of Tories standing down showed there was “no confidence” in Rishi Sunak and the Conservative Party’s prospects.

But Treasury minister Gareth Davies denied this was the case, telling Sky News he was “personally sad” to see Mrs May stand down, but that it was “completely reasonable” for people to decide to leave Parliament ahead of an election.

He said: “Each one has made their own decision for personal reasons and I respect every single person’s decision to do so.”