The British Prime Minister Theresa May has again insisted that there can be no new regulatory barriers between Northern Ireland and Britain after Brexit.

Mrs May made a statement at Downing Street this afternoon after her ‘Chequers’ plan for Brexit faced strong criticism from EU leaders during a summit in Austria yesterday.

She claimed the UK has shown The EU "respect" throughout the negotiations and said it is now time to "hear from the EU" on how to move forward the negotiations.

Her call comes despite the fact that the EU has already come forward with detailed Brexit plans, which the UK has rejected.

In her speech, Mrs May said keeping the UK in the Customs Unions would not respect the integrity of the Brexit referendum, while asking the North to observe different regulations from Britain would threaten the integrity of the UK.

"Northern Ireland would remain in the Customs Union and parts of the Single Market - permanently separated economically from the rest of the UK by a border down the Irish sea," she said.

"Parliament has already unanimously rejected this idea.

"Creating any form of customs border between Northern Ireland and the rest of the UK would not respect that Northern Ireland is an integral part of the UK - in line with the principle of consent as set out in the Good Friday Agreement.

"It is something I will never agree to.

"Indeed, in my view it is something no British Prime Minister could ever agree to.

"If the EU believe I will, they are making a fundamental mistake."

Stormont

However she did leave the door open to such an arrangement in the future - provided the political impasse at Stormont can be broken and devolved Government restored.

"We will set out our alternative that preserves the integrity of the UK and it will included the commitment that no new regulatory barriers should be created between Northern Ireland and the rest of the UK, unless the Northern Ireland Executive and Assembly agree," she said.

She insisted however that anything that "fails to respect the referendum" or "effectively divides" the UK in two would be a "bad deal," adding "I have always said: no deal is better than a bad deal."

She said her Chequers plan offers a third option and insisted it is "the best way to protect jobs here and in the EU and avoid a hard border between Ireland and Northern Ireland."

"Respect"

She also took aim at EU leaders over their rejection of the Chequers plan - and claimed that it was up to them to come forward with solutions.

"Throughout this process, I have treated the EU with nothing but respect," she said. "The UK expects the same."

"A good relationship at the ends of this process depends on it.

"At this late stage in the negotiations, it is not acceptable to simply reject the other side's proposals without a detailed explanation and counter-proposals.

"So we now need to hear from the EU what the real issues are and what the alternative is so we can discuss them.

"Until we do we cannot make progress. In the mean time we must and will continue to prepare ourselves for no deal."

The Chequers plan would see the UK sharing a common rulebook with the EU for goods and services in an attempt to prevent a return of customs checks on the border. 

File photo of Jeremy Corbyn, 04--9-2018. Image: Nick Ansell/PA Wire/PA Images

Earlier the Taoiseach Leo Varadkar said that the Chequers plan can have some input into the talks - but noted that there are obvious problems with it.

He said it is not Europe's fault that the plan did not get a better reception in Salzburg.

"Perhaps a sense was created that Prime Minister May would come away with something more positive than what occurred but I don't think anyone in the EU or Ireland is to blame for that," he said.

"Ultimately, the problems that are being created for Britain and the British Government in as a consequence of Brexit.

"Nobody in Europe or Ireland can be blamed for that."

However, he insisted it was till possible to reach a deal.

"We are entering into a rocky patch over the next couple of weeks but I am determined to keep working and to secure that deal that we need before the end of the year - and ideally in October or November," he said.

"Not an option"

Following the speech, UK Labour Party leader Jeremy Corbyn said: "Theresa May's Brexit negotiating strategy has been a disaster. The Tories have spent more time arguing among themselves than negotiating with the EU.

"From day one, the Prime Minister has looked incapable of delivering a good Brexit deal for Britain.

"The political games from both the EU and our government need to end because no-deal is not an option."

Salzburg

At the informal gathering of EU leaders in Salzburg yesterday, European Council president Donald Tusk insisted the proposals on the future relationship 'would not work' - while Taoiseach Leo Varadkar dismissed suggestions there had been progress on the Irish backstop to avoid a hard border.

Conservative MP Jacob Rees-Mogg - a prominent pro-Brexit politician - said Mrs May's plan isn't viable, suggesting it would keep the UK "tied into the failing European Union economic model."

Criticising the Chequers plans, he added: "The EU was not going to accept it, and it's not leaving the European Union.

"It won't protect jobs - it will deny us the opportunity to create jobs."

'Walking Chequers up a cul de sac'                   

The European Council summit also came as Mrs May's former Brexit secretary David Davis warned that around 40 Conservative rebels are ready to vote down the Chequers plan - meaning it wouldn't make it through the House of Commons.

In an interview with the Huffington Post, Mr Davis - who resigned over the Chequers proposals - argued: "The argument that this is all that’s on offer is just nonsense."

He suggested a free trade deal similar to those between the EU and Canada, noting: "In November when the alternatives are either no deal or WTO or free trade-plus, free-trade plus will look very attractive.

"The EU will have walked Chequers up a cul de sac because they will try and get more."

German Chancellor Angela Merkel and French President Emmanuel Macron also gave a thumbs down to Mrs May's proposals during yesterday's summit.

Ms Merkel warned there is "still a lot of work to do" before a future trade agreement is reached.

The French President, meanwhile, argued: "We all agreed on this today, the proposals in their current state are not acceptable. The Chequers plan cannot be take it or leave it."

Mr Macron also attacked those who "predicted easy solutions" for leaving the EU as "liars", adding: "What's more, they left the next day so they didn't have to handle it."

Additional reporting from Stephen McNeice