Boris Johnson has written a letter to the president of the European Union outlining his plans to break the Brexit impasse.
In a letter to Jean-Claude Juncker, the prime minister said "both sides now need to consider whether there is sufficient willingness to compromise" to reach an agreement in time.
Mr Johnson said the backstop - the contingency plan agreed by the EU and Theresa May to prevent a hard border between Northern Ireland and Ireland - must be removed.
Unlike Mrs May's plans for a UK-EU relationship with a closely integrated customs arrangement, Mr Johnson favoured a looser free trade deal and "in these circumstances the proposed 'backstop' is a bridge to nowhere".
Mr Johnson claimed the plan was "entirely compatible with maintaining an open border in Northern Ireland".
In response to his plans, Plaid Cymru's Liz Saville-Roberts MP described it as a "fantasy deal, full of contradictions, from an utterly desperate Prime Minister.
"If he had a shred of responsibility, he would take this whole question back to the people in a referendum, giving people the final say on our place in Europe.
In a speech at the Conservative Party Conference, Welsh Secretary Alun Cairns reiterated the prime minister's calls to "get Brexit done".