
Instead it would see Britain staying tied to the EU's customs union for up to another year after an nearly two-year transition period if there were any delay in implementing a Brexit deal.
The EU backstop option has been rightly criticised for reducing the single market "access of Northern Ireland to ... goods, including agricultural and electricity".
"The UK is clear that the temporary customs arrangement, should it be needed, should be time limited", said the document.
But within minutes of concluding a press conference in Brussels, Mr Barnier took to Twitter to correct the impression that he was rejecting the United Kingdom proposals out of hand, stressing that they would be the subject of discussions in the coming days and weeks.
This arrangement is meant to keep Britain tied to the bloc's customs union after a transition period should there be a delay in implementing a final Brexit deal that has yet to be reached with Brussels.
"Best for Britain" said it was lobbying 70 MPs to "swing the Brexit debate" in parliament and wanted them to legislate in October to hold a referendum in March.
At the heart of the problem is ensuring there is no hard border between the British province of Northern Ireland and the Irish Republic, which will remain in the EU.
The alternative was for Northern Ireland to have a "special status", distinct from the rest of the UK. "Because it has been designed for the specific situation of Northern Ireland". "What is feasible for a territory the size of Northern Ireland is not necessarily feasible for the whole United Kingdom".
Others questioned the substance of the proposal.
More news: Mamnoon Hussain, Xi discuss regional security, global issues in SCO summit"The UK calls this arrangement "temporary", said Mr Barnier.
Britain leaves the European Union without any agreement on future relations, and trades on World Trade Organisation terms. "How does that fit with the requirements of our Value-Added Tax system?" It made a partial proposal on Thursday - after much domestic wrangling - and the European Union said on Friday that while it's prepared to keep talking about it, some key elements of the plan won't work.
"What we need to see at the June summit is meaningful progress".
"The time has come today to take decisions and make choices", Barnier said.
A new campaign for a second referendum on the U.K.'s exit from the European Union, which is allegedly partly sponsored by US billionaire George Soros, has been launched in London on Friday.
"This is nothing more than an outrageous attempt to revert to the annexation of Northern Ireland".
He warned, though, "We do not accept an à la carte approach, including to the single market".
"Mr Barnier fails to understand that both the Labour Party and the Conservative Party have already indicated that his proposed backstop is not acceptable".
Soros has agreed to give Best for Britain 500,000 pounds ($671,250), angering some Brexit supporters who say he is seeking to undermine the outcome of the 2016 referendum which resulted in a 52-48 percent result in favour of leaving the EU.