And he told fellow MPs: "If we stay on our current trajectory, we will go into the next election with the Government having delivered none of the benefits of Brexit, with the country reduced to being a rule-taker from Brussels, and having failed to deliver on a number of promises in the manifesto and in the Lancaster House speech".
It highlights how Theresa May's "precious Union" has little meaningful support among the British prime minister's own supporters or those in other parties who regard themselves as unionist. "The electoral consequences could be dire".
He replied that "whilst it may be theoretically possible for us to do that, we can not do it and have a deal with the EU", adding: "The EU are not offering us Canada, super Canada, an FTA without keeping to the commitment that we made when he was in Government in December to come up with a legally binding backstop, so that is a shortcut to no deal and we've always said that we'd be ready if that outcome is forced on us, but the optimum aim here, the optimum objective that we're working towards is a good deal with the EU. The issue now is that the ball is firmly back in the EU's court".
Downing Street was quick to pour cold water on the free trade agreement put forward by the EU.
He said: "If Britain crashes out of the European Union without a deal on anything, then you are talking about carnage in that scenario, particularly for Britain". And I'm going to do everything I can to ensure that is the best deal possible.
According to one of the academics who conducted "The Future of England Study", unionists' preference for Brexit over the territorial integrity of the United Kingdom "raises questions about the type of union we're in, and indeed what unionism means".
He added: "It is time for the European Union to match the ambition and the pragmatism that we have shown".
In a further blow to No.10, the Democratic Unionist Party (DUP) also warned that it should not try to "bounce" its MPs into backing the government's plans to avoid a hard border in Northern Ireland.
Reports had suggested that deadlock over the so-called "backstop" arrangements for Ireland could be broken by permitting checks on exports from the mainland to the north, but not in the opposite direction.
Ahead of a meeting with EU Brexit negotiator Michel Barnier in Brussels, DUP leader Arlene Foster stuck to her rejection of any new regulatory or customs barriers inside the United Kingdom - but said that, with political will, a deal was possible.
"It's not just a case of regulations between Northern Ireland and GB, it's also between GB and Northern Ireland".
"The Prime Minister understands our position and I expect her to respect that position".
But she suggested that the Prime Minister may have to amend her Chequers plan to get a final deal, saying that "we don't know where this is going to end up".