PARIS (Reuters) - France on Tuesday rejected any renegotiation of the EU-UK divorce deal and urged Britain to make credible proposals after British lawmakers passed a motion instructing their government to secure changes to a key element of the deal.

The lawmakers told May that, for them to accept the divorce deal, she must negotiate to replace the so-called Northern Irish backstop with an unspecified “alternative arrangement”.

The backstop is aimed at keeping an open border between EU member Ireland and British-ruled Northern Ireland after Brexit. It is strongly opposed by many in Prime Minister Theresa May’s Conservative Party, who say it risks trapping the UK in a permanent customs union with the European Union.

“The withdrawal agreement and the ‘backstop’ were adopted by the British government and the 27 jointly in November. This agreement cannot be renegotiated. The EU has been clear on this point,” the French president’s office said in a statement.

“If, on the other hand, Britain wants to discuss the future relationship with the EU or open a new process (elections, referendum, etc.) that it has to determine, the EU is open to it, with respect for its interests and values.”

Macron’s office said the French government would push ahead with preparations for a “no-deal” exit.

“In any case, it is urgent that the United Kingdom clarify its intentions and make credible proposals,” the statement said.