Theresa May has criticised a “coarsening” of political debate in recent years after announcing she will stand down at the next general election, bringing a 27-year career in Parliament to an end.

The former prime minister on Friday joined an exodus of Tories from the Commons, citing a desire to focus on supporting causes including the fight against modern slavery.

But she also found fault with the current political climate in an article for The Times newspaper, saying she had seen “less respect for others’ views” over the course of her time in Parliament.

“Democracy depends on us being able to debate key issues that affect people’s everyday lives seriously and respectfully,” Mrs May said.

“It needs politicians who put those they represent first and themselves second. It needs MPs who are there to serve.”

The former PM, whose tenure in Downing Street was dominated by bitter wrangling over Brexit, also said it was important to remember “compromise isn’t a dirty word”.

In a statement given earlier to her local newspaper, the Maidenhead Advertiser, Mrs May 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, 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 as she attempted to chart a course through the wake of the UK’s 2016 EU referendum. 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.

Following her announcement, Mrs May continued with her constituency duties, visiting a primary school where pupils were taking part in a scheme to get girls playing football on International Women’s Day.

Paying tribute, Prime Minister Rishi Sunak described 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.”

Foreign Secretary Lord Cameron, from whom Mrs May took over as prime minister in 2016 during a period of extraordinary turmoil after the Brexit vote, said: “As well as serving as my home secretary and then as PM, she did much to help modernise the Conservative Party and promote women in public life. She has been the most dedicated of public servants. The House of Commons will miss her.”

Chancellor Jeremy Hunt tweeted: “Theresa May is the best kind of public servant and was an excellent boss when she was PM!

“I wish her the best in her future career. The House of Commons will miss you.”

Home Secretary James Cleverly said she had been “a dedicated parliamentarian and public servant throughout her career”.

Tory former cabinet minister Sir Sajid Javid, who is also not standing at the next election, said: “Parliament will miss her strong personal qualities of decency, integrity and commitment to public service.”

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 Mrs May’s departure marked the “end of an era” and the number of Tories standing down showed there was “no confidence” in Mr 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.”