A senior Democratic Unionist Party (DUP) figure told CNBC Tuesday that politicians in Brussels would clamour for fresh terms of trade with the U.K. should the country leave the European Union with no deal.
Sammy Wilson, the Brexit spokesman for the Northern Irish party, added that his party would not support the current deal set to be voted on in Parliament on Tuesday night.
Wilson, whose party props up May's minority government in Westminster with, told CNBC's Steve Sedgwick that a "no-deal" Brexit would spur the EU into fresh talks.
"I believe once we are in that situation, reality will kick in Brussels and they will come back and negotiate a realistic trade deal, rather than the one we have got at the moment," he said.
Wilson said lawmakers in Brussels would urgently seek talks in order to protect their large surplus on trade.
According to a U.K. Parliament report, the EU had an overall trade surplus of £67 billion ($86 billion) with the U.K. in 2017. A deficit of £28 billion on trade in services was outweighed by a surplus of £95 billion on trade in goods.
A crucial vote on U.K. Prime Minister Theresa May's Brexit plan is set to take place on Tuesday night in the House of Commons, the lower house of Parliament.
The DUP has confirmed that in this instance it will vote against the government deal, claiming it will result in Northern Ireland being treated differently that the rest of the United Kingdom.
Mood music surrounding Westminster has suggested that May's government is on course to register a heavy defeat, creating fresh uncertainty about Britain and Northern Ireland's future relationship with the EU.
There is some speculation that May could even resign if her proposal is soundly rejected and Wilson said while he expected May to stay on, any new leader of the Conservative Party should be someone who believed in Brexit.
"We are not interested in who leads the Conservative Party. We would prefer it would be someone who actually believes in what the referendum produced and tried to deliver on that," he said.