Prime Minister Theresa May has ruled out removing the Irish backstop from the Withdrawal Agreement, claiming the “insurance policy” prevents a “hard border.”

Mrs May described her commitment to maintaining the Good Friday Agreement and avoiding a hard border as “unshakeable,” in a speech to business leaders in Belfast on Tuesday, telling media, “I’m not proposing to persuade people to accept a deal that does not contain that insurance policy for the future.

“What Parliament has said is that they believe there should be changes made to the backstop,” which the prime minister said would prevent a hard border between Northern Ireland and the Republic of Ireland.

“It is in that vein, in that light, that we are working with politicians across Westminster, across the House of Commons… with the Irish government and with the EU — to find a way that enables us to maintain our commitments that we have set very clearly for no hard border.”

The Withdrawal Agreement had been voted down in the House of Commons last month over the backstop, which could permanently lock Northern Ireland in regulatory alignment with the EU should London and Brussels not agree a deal on their future relationship by the end of the transition period in December 2020.

Mrs May continued, “The issue that has always been one that parliament has raised — it has been raised across all sides of the House of Commons — is the potential indefinite nature of the backstop.

“That’s the issue we look to address. There are a number of ways to do it: looking at alternative arrangements, discussing with MPs who put forward proposals on that, looking at the changes to give legal certainty.

“But the commitment to no hard border absolutely remains, as Sir Graham Brady’s amendment that passed the House of Commons made clear, commitment to no hard border and to leave the European Union with a deal.”

Mrs May is set to meet with leaders from Northern Ireland’s parties on Wednesday. Arlene Foster, whose Democratic Unionist Party (DUP) props up Mrs May’s minority Conservative Government, said ahead of the prime minister’s speech that the backstop has to be replaced, calling it “toxic.”

“We will be reiterating our opposition to the current backstop and the fact that Parliament has now backed that position means she has a clear mandate to go back to Brussels,” Ms Foster said.

“Parliament’s mandate is to replace the backstop, the current backstop,” she added.

The DUP has maintained that there would be no need for the backstop to keep Northern Ireland in a customs union to prevent a so-called “hard border” as goods with difference taxes and excise duties move across the border daily.

Fellow Irish unionist Lord Trimble, former leader of the Ulster Unionist Party who was awarded a Nobel Peace Prize for his work on the Good Friday Agreement, announced Monday that he backs taking legal action against the Government over the Withdrawal Agreement, saying the backstop could damage the peace deal and “do serious damage to Northern Ireland and Northern Ireland’s place in the UK.”