Prime Minister Theresa May is struggling to find a proposal on post-Brexit customs arrangements - the biggest stumbling block so far in exit talks - to take into negotiations with Brussels as the clock ticks down to Britain's scheduled exit in March 2019.
A 10-mile wide "special economic zone" would be created along the 310-mile border, within which local traders could operate under the Republic's trade rules.
The government today denied reports that its civil servants have predicted chaos at ports and food, medicine and fuel shortages within a fortnight of a "no deal" Brexit.
"Once again this shows the lack of knowledge of border areas and the concerns they face".
"The creation of a buffer zone would merely move the problem away from the border and hide a hard border in a buffer zone".
DUP MP Sammy Wilson also said the idea was "nonsense".
"None of these proposals have been discussed with the DUP and at first examination they appear to be at best contradictory".
The Democratic Unionist Party (DUP), which props up Prime Minister Theresa May's minority government at Westminster, will nearly certainly be opposed to the new proposals, as they have said they will not accept Northern Ireland leaving the bloc on different terms to the rest of the United Kingdom. Do checks have to be carried out there?
A spokeswoman for the Department for Exiting the European Union declined to comment.
There will be no "Armageddon" if Britain fails to agree a Brexit deal with the European Union, Downing Street has insisted.
"To suggest that Northern Ireland be tied to both EU and UK regulations, when one of the objectives of leaving the [EU] Single Market is to allow the UK to set its own regulations, raises the question which regulations apply to Northern Ireland if and when the UK and the EU regulations diverge", he said.