"The Irish position remains consistent and v clear that a "time-limited backstop" or a backstop that could be ended by United Kingdom unilaterally would never be agreed to by Ireland or the European Union", Irish Foreign Minister Simon Coveney said on Twitter.
Britain is looking for an agreement based on an improved version of the EU's "equivalence" system of financial market access, whereby Brussels allows foreign firms to operate on its turf if their home rules are closely aligned with those in the bloc.
Brexit is undermining Northern Ireland's hard-won peace by creating tensions between Catholic and Protestant communities, Irish Prime Minister Leo Varadkar said on Saturday, even as hopes rose for a solution to the Irish border problem that has deadlocked negotiations.
Therefore in order to get the current iteration of the backstop through cabinet, the PM must persuade ministers that the EU has no intention to trap the United Kingdom in a customs union in perpetuity.
The Taoiseach has said Brexit has undermined the Good Friday Agreement and is fraying relations between Ireland and Britain.
However, in order for the EU to accept this compromise, Mrs May must convince her colleagues and the DUP to agree that Northern Ireland can only opt out of the customs union when another mechanism of ensuring a soft Border is agreed.
However, while it was backed by 63 per cent of people who voted Remain, it was backed by just 20 per cent of Leave voters.
"We think there are answers to the practical issues involved".
Justice Secretary David Gauke warned that a no-deal Brexit would be bad for the UK.
Negotiators are trying to find an emergency Irish border fix that would satisfy Ireland, the Democratic Unionist Party and May's divided Conservative Party.
"If we can get a good deal, and that means removing all the frictions... the Chequers-type deal, as I say, if we don't have friction with trade, then, economically, I don't think it's going to make a particular big difference one way or the other".
According to the Sunday Times, the agreement would include an "exit clause" aimed at convincing Brexiteers that remaining in the customs union would be temporary.
The national poll of over 20,000 by Survation indicates a six per cent swing in voter intentions with 54 per cent saying they would vote remain if given the chance.
Following the 2016 referendum on EU membership, which resulted in a vote to leave the EU, the British government triggered the withdrawal process under Article 50 of the Treaty on European Union on March 29, 2017.