The UK needs to remain in the European Convention on Human Rights (ECHR) as it has shown a willingness to “row back” on international law, Theresa May has said.

The former prime minister had previously expressed frustration with the ECHR and in 2016 suggested the UK should leave the treaty as it could “bind the hands of Parliament”.

But asked on Thursday whether she still thought the UK should look to leave or reform the ECHR, Mrs May said she now thought Britain should remain in the convention.

She told a press gallery lunch in Westminster: “That’s partly because circumstances have changed, also because sadly we have shown as a country a willingness to row back sometimes on certain aspects of international law.

“I think we should stay in something that we helped to create in the first place.”

The ECHR has become a significant issue for members of the Conservative right, and the Prime Minister himself has indicated he would be willing to leave the treaty if it prevented him deporting asylum seekers to Rwanda.

Answering questions from journalists on Monday, Rishi Sunak said: “If the Strasbourg court make me choose between the ECHR and this country’s security, I will choose our country’s security every single time.”

Mrs May has been an opponent of the Rwanda scheme, saying it would make it harder to tackle modern slavery.

In a further rebuke to the Tory right, Mrs May rejected the suggestion that Reform UK leader Richard Tice and party president Nigel Farage should be welcomed into the Conservative Party.

Some Conservatives believe neutralising the threat from Reform would prevent the Tories losing voters to their right and save key marginal seats currently held by the party.

On Tuesday, former cabinet minister Sir Jacob Rees-Mogg used his GB News show to argue that the Tories should give Mr Farage a job in Government and welcome Mr Tice and other Reform UK politicians, saying this would put an election victory “within reach”.

But Mrs May said she disagreed, adding: “I don’t think Nigel Farage is a conservative, I don’t think Richard Tice is a conservative. They are in a different party, that’s it.”

She also rejected the suggestion that the result of the upcoming election was a foregone conclusion, saying Sir Keir Starmer lacked the popularity of Tony Blair and Labour faced a tough task in winning the number of seats it needs even for a majority of one.

Referring to the 2017 election, which saw her lose her majority despite beginning the campaign around 20 points ahead of Labour, she added: “We’ve seen a lot of unexpected election results in recent times.”

Mrs May made her remarks during what will be her final months in Parliament, as she is due to stand down as MP for Maidenhead at the coming election after 27 years in the Commons.