A new text on the Brexit agreement reached earlier this week is being examined by the Irish and British governments, as well as the EU.

Taoiseach Leo Varadkar and British prime minister Theresa May spoke on the telephone for 15 minutes on Thursday evening.

The wording of the new text is understood to have been tabled by London. Mrs May is seeking to assuage DUP concerns as the party supports her Conservative government in the House of Commons. Taoiseach Leo Varadkar’s spokesman said: “Matters are being considered as part of ongoing discussions involving the (EU) task force, the Irish Government and the British government.”

A spokesman for European Commission president Jean Claude Juncker said both Mr Varadkar and Mrs May had spoken to Mr Juncker on Thursday.

“We are making progress but not fully there yet,” Margaritis Schinas said. “Talks are continuing through the night.”

Meanwhile, Brexit lead transport secretary Chris Grayling, one of the most prominent Brexiteers in the Cabinet, said he remained optimistic a resolution could be found to the Border impasse.

Businesses in the Republic of Ireland would suffer if no agreement was reached, he warned.

He said that the “regulatory alignment” proposed by British prime minister Theresa May in Monday’s text – a phrase which alarmed the DUP – did not involve laws within the post-Brexit United Kingdom being the same as those in the rest of Europe.

“We don’t have to have, we have never said we will have and we don’t want a situation where in future our laws are identical to those of the EU,” he said.

“There will be areas where we do things in a very similar way, there are will be areas where we don’t do things in a similar way. That’s all the prime minister was seeking to achieve, to make sure we can ensure that trade flows as freely as possible across the Border.”

Foreign secretary Boris Johnson said any Brexit deal must stick to the spirit of the Leave campaign.

“It is very, very important that whatever happens now, whatever we agree, has got to be consistent with taking back control of our laws, of our borders and of our cash,” he said.

Mr Johnson said the UK was making a “very good” financial offer to the EU, and when he had said people could “go whistle” for a large exit settlement he was referring to amounts between £80 billion – £100 billion.

“I was asked my reaction to some of the very extortionate sums that I had heard in the region of £80 or £100 billion, and, I don’t want to repeat the offending phrase, but go whistle seems the appropriate reaction to that kind of money,” he said.

Pressed on whether he was comfortable with a widespread regulatory alignment between the UK and EU after Brexit, the foreign secretary said: “You can take it from me that whatever comes up, whatever the solution that we come to . . . it’s got to be consistent. It’s got to be consistent with the whole of the United Kingdom taking back control.”

On Thursday, members of the House of Commons Brexit committee visited parts of the Border to hear from local people about their concerns.

Additional reporting – (PA)