LONDON (Reuters) - Prime Minister Theresa May will never agree to a backstop plan to prevent a hard border with European Union member Ireland that means Britain could be permanently tied to the bloc’s customs rules, her spokeswoman said on Friday.

Britain’s international trade, environment and Brexit ministers told Prime Minister Theresa May at a meeting on Thursday that they are concerned the whole of Britain could remain in the customs union for an open-ended period of time, the BBC said.

“The prime minister would never agree to a deal which could trap the UK in a backstop permanently,” the spokeswoman told reporters.