LONDON (Reuters) - Britain is more likely to leave the EU without a deal if lawmakers reject the agreement Prime Minister Theresa May has negotiated, one of her ministers said on Thursday, as a second said a no-deal exit would hit the farming sector hard.

FILE PHOTO: Britain's Secretary of State for Exiting the EU Stephen Barclay arrives in Downing Street, London, Britain, December 18, 2018. REUTERS/Hannah McKay

Brexit is scheduled for March 29 but, while Stephen Barclay and Michael Gove both warned against an unmanaged departure, what will actually happen on that day remains far from clear.

The future of May’s agreement hangs in the balance in the run-up to a parliamentary vote, and calls for a second referendum - which she has consistently rejected - are growing.

“No deal will be far more likely if MPs (Members of Parliament) reject the government’s Brexit deal,” Brexit minister Barclay wrote in the Daily Express newspaper, arguing that May’s plan was the only “workable deal” available.

Environment minister Gove said British farmers and food firms would face rising costs in the event of no deal, as export tariffs kicked in and border inspections slowed traffic through ports.

Lawmakers must choose whether to accept May’s plans for a structured exit and relatively close economic ties, or reject it and spawn huge uncertainty about the country’s next steps. The vote is due in the week beginning Jan. 14.

NO-DEAL PREPARATIONS

The main barrier to May’s deal is opposition to a ‘backstop’ designed to prevent the return of a hard border between Northern Ireland and EU state Ireland if a better solution to maintain free-flowing trade is not agreed.

Critics argue it could leave Britain trapped inside the EU’s customs union indefinitely.

May is seeking extra reassurances from Brussels to help persuade skeptical lawmakers within her own party and the small Northern Irish Democratic Unionist Party (DUP) that props up her minority government.

DUP Deputy Leader Nigel Dodds said after talks with May on Thursday that its objections to her deal remained.

Ireland’s Prime Minister Leo Varadkar said the EU would not accept clarifications or reassurances on the deal that would undermine its spirit or render any of it inoperable.

Within Britain’s opposition Labour Party, which has so far backed a negotiated exit but does not support May’s deal, there is growing support for a second Brexit referendum. But the Guardian newspaper reported that its leader Jeremy Corbyn would resist such a policy change.

Sterling has fallen against the dollar in recent weeks, in part due to growing concerns over the course of the Brexit process.

Barclay, whose main remit is to make sure Britain is ready in case a deal cannot be reached, said the government would step up those preparations next week. “On Tuesday we will start a new phase in our public information campaign,” he wrote.

A new government website will contain advice on what no-deal preparations businesses, Britons, and EU nationals living in the country should make. Billboard advertisements for the website will appear in coming weeks.