Addressing MPs to present assurances on the Irish border backstop issued by the EU on Monday, the Prime Minister said that no deal was the “real threat to our Union”.
Mrs May’s government has previously insisted that “no deal is better than a bad deal”, and dismissed any suggestion that a second independence referendum could take place as a result of Brexit.
But in an appeal to try save her Brexit deal ahead of Tuesday’s crucial Commons vote, the Prime Minister warned of the risk no-deal would pose to the survival of the UK.
“Surely this is the real threat to our Union.”
An exchange of letters between Mrs May and EU chiefs failed to secure a firm end date for the backstop, which will come into force if a trade deal that prevents a hard border in Ireland isn’t agreed by the end of 2020.
The backstop would see the whole UK remain under EU customs rules, but would also see a different set of EU regulations apply in Northern Ireland from the rest of the UK.
The backstop has infuriated Tory Brexiteers and the government’s DUP allies, who said on Monday that the assurances were not enough to win their support.
Addressing her critics, Mrs May told MPs: “I fully understand that these new assurances still will not go as far as some would like.
“I recognise that some Members wanted to see changes to the Withdrawal Agreement: a unilateral exit mechanism from the backstop, an end date or rejecting the backstop altogether – although it should be said that this would have risked other EU Member States attempting to row back on the significant wins we have already achieved such as on control over our waters or the sovereignty of Gibraltar.
“But the simple truth is this: the EU was not prepared to agree to this.
“And rejecting the backstop altogether means no deal.
“Whatever version of the Future Relationship you might want to see – from Norway to Canada to any number of variations – all of them require a Withdrawal Agreement and any Withdrawal Agreement will contain the backstop.
And that is not going to change however the House votes tomorrow.”
“No it is not perfect. And yes it is a compromise.
“But when the history books are written, people will look at the decision of this House tomorrow and ask: Did we deliver on the country’s vote to leave the European Union?
“Did we safeguard our economy, our security and our Union? Or did we let the British people down?”