DUP leader Arlene Foster has dismissed a report that the party will offer British Prime Minister Boris Johnson a lifeline to help him unlock a Brexit deal.

She was responding to a front page article in today's Times newspaper that said the DUP had agreed to shift its red lines on Brexit.

The paper reported that the DUP could accept Northern Ireland abiding by some EU rules post-Brexit as part of a new deal to replace the backstop.

The paper claimed the party had also privately said it would drop its objection to regulatory checks in the Irish Sea, something it had previously said was unacceptable since it would separate Northern Ireland politically and economically from the mainland.

The Times, citing unidentified sources, wrote that in return for such concessions Brussels would abandon its insistence on Northern Ireland remaining in a customs union with the EU.

However, Mrs Foster insisted that, as previously indicated, any moves that made Northern Ireland different to the rest of the UK would be unacceptable to the party.

"UK must leave as one nation. We are keen to see a sensible deal but not one that divides the internal market of the UK," Ms Foster tweeted.

"We will not support any arrangements that create a barrier to East West trade.

"Anonymous sources lead to nonsense stories."

UK must leave as one nation. We are keen to see a sensible deal but not one that divides the internal market of the UK. We will not support any arrangements that create a barrier to East West trade. Anonymous sources lead to nonsense stories. #frontpages — Arlene Foster (@DUPleader) September 12, 2019

Meanwhile, Táiniste Simon Coveney has said the European Union has issues with a future Stormont executive being able to veto aspects of the Irish border backstop.

Speaking at the Fine Gael party think-in in Co Cork, Mr Coveney said any alternative arrangements to replace the backstop and the Withdrawal Agreement will be "rigorously tested".

The British government has previously proposed that if the Irish backstop came into operation, the devolved legislature in Belfast would have to agree to any subsequent changes to EU laws impacting on it.

"We will explore all ideas that are being brought forward by the British government but they will be rigorously tested because this has to stand up to real scrutiny," he said.

"It's got to be negotiated in Brussels between the team for the UK and Michel Barnier's Task Force. I think that's where these ideas get tested.

"I think there is certainly a concern at an EU level that a devolved institution in Northern Ireland could have a veto over how the single market operates or a border on the single market operates, so it's not as straightforward as some people are suggesting."

Mr Coveney said there are no detailed proposals being put forward by the British government, and that it is a source of frustration in Europe.

He added: "We don't have detail of proposals that have come forward from the British government. I mean, there essentially aren't detailed proposals in writing, which has been a source of real frustration, particularly for the Barnier task force.

"And I think you saw that yesterday when Michel Barnier said at the moment, there's no basis for the reopening of a serious negotiation, because there's no proposals coming forward."