Boris Johnson is expected to make detailed Brexit proposals in the coming days, but Ireland has already ruled out a "non-beginner" border plan.
The prime minister will offer his plan for a Brexit deal to the EU following this week's Conservative Party conference in Manchester.
Johnson promised to renegotiate the current UK withdrawal agreement and demanded the abolition of the Irish border setback agreement.
The backdrop was designed as an insurance mechanism to avoid a difficult border on the island of Ireland, regardless of the future EU / UK trade relationship.
RTE reported late Monday that Johnson's plan to replace the jamb could include "customs clearance sites" on either side of the border between Northern Ireland and the Republic of Ireland.
That could be about five or five miles away, the Irish broadcaster added.
The plan was said to be included in one of four "non-documents" presented by UK authorities during recent discussions in Brussels.
A non-paper document is an informal document, usually used to test the reaction of other parties to possible solutions without necessarily compromising the proposer.
Paragraph 10 rejected the suggestion that the United Kingdom would propose a "series of inspection posts" as RTE claimed that the plans were indeed equivalent.
Unofficial document from the United Kingdom discussed a mechanism by which customs procedures would be conducted at the origin or destination of the goods.
The place of inspections would be for the customs authorities to decide and could be at the destination or specific premises, but most would be expected to be well off the border.
A Downing Street spokesman said: "Nothing we are proposing involves border checks or controls.
"This is an absolute commitment."
No paper = not initiator. When the EU received a serious proposal from the UK Government if a #Brexit business is expected to be reached in October. NI and IRE deserve better!
– Simon Coveney (@simoncoveney) September 30, 2019
Irish Foreign Minister Simon Coveney tweeted: "Non-Paper = Non-Starter. Time when the EU received a serious proposal from the UK government to make a #Brexit deal possible in October. NI and IRE deserve better! "
And an Irish government spokesman said he had not yet seen "reliable alternatives" to the current scenario.
They said: "The EU task force has indicated that all documents not received from the UK so far fall far short of the agreed backstop objectives and targets.
"The UK documents were handed over to the task force with the strict understanding that they would not be shared with anyone. The task force stated that it did not receive credible proposals from the British.
"Ireland's priorities are protecting the Good Friday Agreement, avoiding a difficult border and protecting the entire island economy and protecting the EU single market and its benefits for Irish businesses and consumers.
"We still have to see reliable backstage alternatives."
Brexit shadow secretary Sir Keir Starmer said the reported plans were "totally impractical".
"They would put a huge administrative burden on companies and depend on technology that doesn't exist yet," he said.
"Crucially, if true, they represent a return to the commitments made to the people of Northern Ireland two years ago that there would be no return to a rigid border or related checks or controls.
"If needed, these proposals represent yet another failure of the government's negotiating strategy."
Dublin says it has not yet received "credible alternatives" behind the scenes
The emergence of the disputed Irish border plan came before the third day of the Tory conference in Manchester, during which Secretary of Justice Robert Buckland will set plans for longer-term sexual and violent offenders to be held behind bars.
Meanwhile, Interior Secretary Priti Patel will use her own speech at the conference to tell Tory members that "it will renew our place as a party of law and order in Britain."
Patel, the daughter of Ugandan Asians, will also say, "Margaret Thatcher knew that if you made the British people your compass, if you took some time to understand their lives and their priorities, your guidance would always be true.
"This immigrant daughter does not need lectures from the North London metropolitan liberal elite about how our country is enriched by – and better yet – internationalist."