Boris Johnson has claimed that border proposals from the UK reported as new plans were ‘out-of-date’.
It had been understood the legal text of a Brexit plan will be sent to Brussels after the Tory conference concludes on Wednesday.
Irish broadcaster RTE reported the UK had put forward the idea of custom clearance centres being set up five to ten miles either side of the Irish border.
However, government sources distanced themselves from parts of the reports.
Boris Johnson told BBC Breakfast: “As far as I can make out from what I have seen of the response from Brussels and, I think, Dublin, they are not talking about the proposals that we are actually going to be tabling. They are talking about some stuff that went in previously…
“We’ve made a very good offer, we are going to make a very good offer, we will be tabling it formally very soon.”
The reported plans by the British government to create customs posts along both sides of the Irish border to replace the backstop were dismissed by Irish deputy premier Simon Coveney.
Coveney poured cold water on the plans, saying Northern Ireland and the Republic of Ireland “deserves better.”
He tweeted: “Non-Paper = Non-Starter. Time the EU had a serious proposal from the UK Govt if a #Brexit deal is to be achievable in October. NI and IRE deserves better!”
Shadow Brexit secretary Sir Keir Starmer tweeted: “If Boris Johnson had spent any time listening to businesses and communities in Northern Ireland, he would know that these proposals are utterly unworkable.”
Sin Fein leader Mary Lou McDonald said the leaked proposals to change the backstop put forward by the UK over Brexit were “essentially” a return to a hard border in Ireland.
Asked whether she could back such draft plans, she said: “Absolutely not.”
The Irish politician said: “What has been described in this document is essentially a hard border on the island of Ireland.
“Anything that causes there to be customs, tariffs, checks anywhere represents a hardening of the border.”
Speaking to BBC Radio 4’s Today programme, McDonald said the UK’s backstop changes amounted to a “sabotage” of the peace process in Northern Ireland.
“We have explained this (the importance of no border checks) in painstaking detail to Mrs May in her time and now prime minister Boris Johnson,” the leader of the pro-united Ireland party added.
“Privately both always said that they understood that and therefore it is all the more disgraceful that they would try and sabotage the peaceful dispensation on our island.
“Boris Johnson voted for the backstop because in a moment of perhaps rare lucidity he recognised that was the bottom line to protect the island of Ireland. I only hope he returns to that position.”