Taoiseach Leo Varadkar has told British prime minister Theresa May that Ireland will consider a “review mechanism” to the controversial backstop plan at the heart of the Brexit talks impasse.

The two leaders spoke by phone on Monday morning and a statement from Government Buildings said Mrs May “sought the call in order to update the Taoiseach on the current state of the Brexit negotiations”.

Mrs May is under pressure from within the UK to find a method to end the backstop - which will avoid a hard border in Ireland even if there is no future UK-EU trade deals.

“Both leaders emphasised their commitment to avoiding a hard border and the need for a legally operable backstop,” the statement said.

“The Prime Minister raised the possibility of a review mechanism for the backstop. The Taoiseach indicated an openness to consider proposals for a review, provided that it was clear that the outcome of any such review could not involve a unilateral decision to end the backstop.

“He recalled the prior commitments made that the backstop must apply ‘unless and until’ alternative arrangements are agreed,” the statement added. “They both expressed the hope that the negotiations could conclude in a satisfactory manner as soon as possible.”

Time limit

Earlier, Mr Varadkar said a three-month time limit on the backstop “isn’t worth the paper it’s written on” and that the UK is in many ways “a divided kingdom”.

Mr Varadkar was responding to a report that Britain’s Brexit secretary Dominic Raab has privately demanded the right to pull Britain out of the EU’s proposed Irish backstop after just three months. According to the Daily Telegraph he put the proposal to Tánaiste and Minister for Foreign Affairs Simon Coveney early last week.

“As a government we’re working very hard to get an agreement, ideally by the end of the year but one thing we can’t countenance is any idea that there’d be a three-month limit on the backstop, a backstop with a three month limit on it or an expiry date on it of that nature isn’t worth the paper it’s written on,” Mr Varadkar told reporters on Monday at the opening of a Dublin social housing development.

“What the UK government has signed up to is a legally operative backstop that will apply unless and until we have a new agreement to supersede it and I think it’s reasonable for us to expect a country like the United Kingdom and a government like the UK government to stand by its commitments.”

Mr Varadkar said it “didn’t help” that the UK is coming forward with new proposals that contradicted previous agreements.

“The United Kingdom in many ways is a divided kingdom. People are split 50-50 on whether they want to leave the European Union or not. The cabinet seems divided, the government seems divided, parliament is divided and that has made it very difficult to come to an agreement,” Mr Varadkar said.

“I’d much prefer to have a United Kingdom and united country to be our partner in these negotiations but we don’t, so we have to work through.”

Review

Speaking in Brussels, where he is attending a meeting of Eurogroup finance ministers, Minister for Finance Paschal Donohoe said a review of the backstop “can only happen if all the different parties want to see a role in making that review happen. And secondly, it can only happen in the context of an actual backstop being in place.

“The British government gave commitments twice in the last year in relation to the need for a backstop and they’ve affirmed now on many, many different occasions their commitment to ensuring there’s no possibility of a return to a hard border on our island,” he said.

“We want to see that commitment being honoured. I believe Prime Minister May is approaching this issue in good faith, but in order for that commitment to be honoured the Government and the EU need to see a backstop in place that could cater for changes that could happen in the future.”

Mr Coveney said in Sunday that the Government and the EU would “never” agree to a time limited backstop.

“The Irish position remains consistent and v clear that a ‘time-limited backstop’ or a backstop that could be ended by UK unilaterally would never be agreed to by Ireland or the European Union,” Mr Coveney said on Twitter.

Entire UK

The Irish Times understands the final deal on Britain’s withdrawal from the European Union is set to include a backstop that will apply to the entire United Kingdom, but will have additional measures for Northern Ireland to ensure there is no hard border.

A Northern Ireland-specific backstop – a guarantee to avoid a hard border even if future trade talks fail – would effectively give way to one that would apply across the entirety of Britain for customs only.

However, the withdrawal agreement would also contain additional measures that would apply on the Irish Border. These are understood to include some extra customs rules as well as rules to ensure the North’s regulations remain in alignment with EU standards.

A senior government source said such “add-ons” do not “change the fact that Northern Ireland remains in the customs territory of the UK”.

“You have one backstop – the main element of which is a UK-wide customs union – to be extended.

It had been previously mooted that there would be effectively two backstops – one for Northern Ireland and one for the UK – but Government figures say this is now unlikely.

Still cautious

Sources in Dublin and Brussels are still cautious about the prospect of a European Council summit being convened later this month to sign off on the Brexit withdrawal agreement.

Mrs May is expected to brief her cabinet on Tuesday, with Michel Barnier, the EU’s chief Brexit negotiator, updating ambassadors of the EU27 on Wednesday.

It was also disclosed that the key stumbling block to a deal is now when the provisions of the backstop will end.

Agreements already reached between the EU and UK say it will remain “unless and until” another solution to avoid a hard border is found, either by way of a future trade deal or by technological solutions.

Transition phase

The UK formally leaves the EU next March and will enter a transition phase which will see it stay in the single market and customs union until the end of 2020. If a future trade deal has not been concluded at that stage, the backstop will then kick in.

It is understood the UK has been pushing for a set time when the backstop will cease to apply but Dublin and Brussels are firm that “unless and until” must remain.

“That is not resolved yet,” said one well-placed source. “It will only be resolved when they accept a formula of ‘unless and until’. It is not a backstop if it expires.”

Periodic assessments of the talks on the EU-UK future trade deal may be made, and the UK may also have the chance to extend the transition period before it ends in 2020.

It is now accepted that regulatory checks on goods travelling from Britain to Northern Ireland can be done at factories and shops rather than at Border crossings, a development of Mr Barnier’s “de-dramatisation” initiative.