LONDON (Reuters) – British Prime Minister Theresa May’s bid to push her Brexit plans through parliament was dealt another blow on Friday when a survey showed most of her own party’s members oppose the agreement and would prefer to leave the EU without a deal.

If lawmakers do not approve the deal, the world’s fifth largest economy is on course to leave the European Union on March 29 without one, a nightmare scenario for many big businesses who fear disruption to trade.

May needs 318 votes to get the deal she struck with Brussels in November through parliament, yet 117 of her Conservative Party’s 317 lawmakers voted against her in a confidence vote on Dec. 12.

That means that, unless she gains the support of some of the 257 lawmakers in the opposition Labour Party – which has said it will not back the deal – she will need to win over swathes of her own party.

Friday’s YouGov survey offered a snapshot of the challenge she faces.

Of 1,215 of the Conservative Party’s rank-and-file members questioned by the pollster, 59 percent opposed May’s deal and 76 percent said warnings over the risks of disruption in the event of a no-deal were “exaggerated or invented”.

The British economy is showing clear signs of slowing with house prices taking a hit, services companies reporting crisis-like pessimism and lending to British consumers grew at its slowest pace in nearly four years.

The pound, which sank to its lowest since April 2017 on Thursday, rose against the dollar to $1.2670.

Just 38 percent of those polled by YouGov said they supported May’s deal.

“Grassroots Tories (Conservatives) are even less impressed than Tory Members of Parliament (MPs),” said Tim Bale, Professor of Politics at Queen Mary University of London, who helps run a study of British political party membership which commissioned the survey.

NO DEAL BREXIT?

Facing defeat in parliament last month, May postponed a vote on the deal and pledged to seek further legal and political assurances from the other 27 members of the EU, which has signaled it could try to allay rebel’s fears but will not reopen negotiations.

The parliamentary vote is now due to take place the week of Jan. 14 and if May’s bid to push her deal fails, the United Kingdom will either leave without a deal or have to delay Brexit.

Pro-Europeans fear Britain’s exit will weaken the West as it grapples with Donald Trump’s unpredictable U.S. presidency and growing assertiveness from Russia and China. It weakens Europe’s economy and removes one of its only two nuclear powers.

Brexit supporters say while there may be some short-term disruption, in the long-term the UK will thrive outside what they cast as a doomed experiment in German-dominated unity and excessive debt-funded welfare spending.

May is seeking assurances from the EU over the Irish ‘backstop’, an insurance policy to avoid a hard border between the British province and EU-member Ireland, which remains the main obstacle to securing the backing of parliament.

The DUP, the Northern Irish party that props up May’s government, said on Friday that it would not support her Brexit deal but that businesses should be relaxed about leaving the EU without an agreement.

With the future path of Brexit still uncertain two and a half years after the 2016 referendum, the British economy was slowing.

Growth slowed to a crawl at the end of 2018, according to a IHS Markit/CIPS UK Services Purchasing Managers’ Index (PMI), showing optimism among services companies has sunk to levels typical of the global financial crisis.

British house prices took a pre-Brexit hit in December, falling by the most month on month since mid-2012 and rising by their slowest pace in nearly six years in annual terms, according to data from mortgage lender Nationwide.