Democratic Unionist Party (DUP) Brexit spokesman Sammy Wilson MP speaks to media after the DUP annual party conference in Belfast, Northern Ireland November 24, 2018. REUTERS/Clodagh Kilcoyne

LONDON (Reuters) - British Prime Minister Theresa May must secure changes to her withdrawal deal with the European Union itself to provide legally-binding assurances on the Irish backstop, the Democratic Unionist Party’s Sammy Wilson said on Tuesday.

“It would have to be a change in the withdrawal agreement,” said Wilson, whose Northern Irish party props up May’s minority government. “There’s no point in having assurances which don’t have the same standing, the same status as the terms of the withdrawal agreement.”

“That will be the big issue which I think the prime minister has to push with the EU when she enters negotiations with them again.”

May has said she would seek further concessions from the bloc to ease concerns about the backstop, an insurance policy to prevent customs checks on the Irish border. However, the EU has ruled out making any changes to the deal struck with May which British lawmakers overwhelmingly rejected last week.