That was clearly on the minds of European Commission officials Sunday as EU leaders gave their backing to the terms of Britain's split from Brussels after 44 years of membership.
In a direct appeal to farmers, she said the industry "deserves better" than the existing Common Agricultural Policy (CAP) framework set out by the EU.
Asked on Sunday if there were any circumstances in which her party would back May's deal in parliament, Foster told the BBC: "no there aren't".
"I am totally convinced this is the only deal possible". My deal delivers for every corner of the United Kingdom and I will work hard to strengthen the bonds that unite us as we look ahead to our future outside of the EU.
An attempt to win Labour support seemed to fall flat when a special briefing for opposition MPs, chaired by de facto Tory prime minister David Lidington, attracted fewer than 30 opposition MPs.
Back at home, she faces strong opposition to her Brexit deal, which she claims is the best available.
May plans to spend the next couple of weeks selling it to politicians and the British public before Parliament's vote in December.
But it's now the job of all of us in Cabinet to make the case to our colleagues, make the case to the country.
"I believe that nobody is winning".
It also said the hit to the public finances - up to 1.8% of GDP under Mrs May's deal or 3.1% with no deal - would "far outweigh" any gains from reduced contributions to European Union budgets, which represent 0.4% of GDP.
The European Commission chief warned the United Kingdom parliament it should not count on any renegotiation ahead of Britain's departure in March, as European Union leaders on Sunday approved a landmark agreement on Britain's exit.
Union stages protest on Black Friday over 'inhuman' working conditions at Amazon
Protesters are demonstrating outside Peterborough's Amazon fulfilment centre today to highlight concerns about working conditions. But Amazon said its European fulfillment network is fully operational and reports to the contrary are "simply wrong".
Boris Johnson, the former foreign secretary and lead campaigner for Brexit, said on Saturday that Britain was "on the verge of a historic blunder". "But I think what all of my colleagues will be doing is thinking about what is in the national interest". "This is the deal".
The House of Commons Treasury Committee confirmed that it will release the assessments as soon as they are received, before questioning Chancellor Philip Hammond, Bank governor Mark Carney and FCA chief executive Andrew Bailey the following week.
In addition to the divorce deal, May and her European counterparts approved a political declaration on the future relationship between the two partners.
Brexit proponent, Boris Johnson, has slammed Prime Minister Theresa May's Brexit plan as a "disaster for this country" while attacking her "servile" negotiating style with the EU.
The 10 Democratic Unionist Party Northern Irish lawmakers propping up the government said at the weekend they will vote against the deal.
"There is a choice which MPs will have to make. Any other deal really only exists in people's imagination". "It would open the door to more division and more uncertainty, with all the risks that will entail", she added.
British Prime Minister Theresa May, waiting in the wings as the other leaders met, joined them once they had given the deal the seal of approval to discuss the next steps on the road to Brexit. "But right now, as the deal stands, she may not be able to trade with the USA, and I don't think they want that at all".
"We are a satellite state - a memento mori fixed on the walls of Brussels as a ghastly gaping warning to all who try to escape". Leaving without a deal could lower output per head as much as 8.7 percent.
At a bittersweet meeting, European Union leaders expressed sadness at the departure of Britain, the first country ever to leave the bloc.
"We should refuse to hand over a large chunk of our £39billion until that deal is done by the end of the so-called implementation period in 2020", he wrote.