As Mrs May prepares for next week's vote, International Trade Secretary Liam Fox refused to rule out backing a no-deal Brexit if the Withdrawal Agreement is voted down by MPs next week.
A deal reached by Prime Minister Theresa May with European leaders previous year calls for a "backstop" under which Northern Ireland would continue to apply many EU rules unless another means can be agreed in future to keep the border open.
"There is a very hard set of choices that have to be made if we were to leave without a deal", business minister Greg Clark told the BBC earlier on Wednesday.
Just 22 days before Britain is due to leave the European Union the two sides are locked in a game of brinkmanship and attempts to reach a mutually acceptable deal could go down to the wire.
The EU believes unrealistic expectations have built up in London.
"Both sides want to find a way through this and we're hoping for that success to happen this weekend in time for the vote".
Britain's Attorney General Geoffrey Cox is seen outside of Downing Street in London, Britain, February 27, 2019.
"We will move swiftly to propose negotiations on this basis in the event that the United Kingdom leaves without a withdrawal agreement,"he said in a statement. This gives passengers and cargo operators the certainty and confidence that they can continue to fly as normal after the United Kingdom has left the European Union".
Treasury chief Philip Hammond warned pro-Brexit lawmakers that they should "think very, very carefully" about the consequences of defeating May's deal and potentially triggering the postponement of Britain's departure.
Britain's chief law officer said Wednesday that Brexit negotiations with the European Union had got to "the meat of the matter", after Northern Ireland's top civil servant warned that a disorderly United Kingdom exit could destabilize both the economy and the peace process.
But, he said a longer delay that went beyond May's European parliament elections would solve little and would leave the EU's future on hold.
British concerns over Brexit centre on a provision created to keep the open border between Northern Ireland and European Union member Ireland.
Their comments come as former Unionist leader David Trimble published an open letter to Britain's Prime Minister Theresa May in which he claimed that fears about Brexit in the North were "groundless".
Also on Wednesday peers in the unelected House of Lords vetoed the Government's Trade Bill, 207-141, calling for the House of Commons to back the United Kingdom joining an EU customs union after Brexit.