Lord Andrew Adonis has insisted that stopping Brexit is in Britain's best interests.
The Labour peer said remaining in the European Union would be the "best thing" to do, amid reports that EU officials are accepting that Boris Johnson is "not bluffing" about embracing a no deal exit.
"Three weeks ago he [Boris Johnson] told us there was a one in a million chance of us crashing out without a deal, then he has put all this money into preparing for no deal," he told talkRADIO's Julia Hartley-Brewer.
"The alternative is so bad that staying in the EU is the best thing for us to do as a country."
The Prime Minister announced £2.1bn for no deal planning last week, but Lord Adonis said Parliament would "always go to stop it".
"I do not believe there will be no deal, because Parliament has repeatedly voted against no deal," he explained.
"Parliament will not agree to anything like the deal on the table because it's no good. It won't agree to no deal. And therefore, as Sherlock Holmes said, you've eliminated the impossible and you're just left with the improbable."
The staunch remain campaigner again floated the idea of a so-called 'People's Vote' on Brexit.
"It rules out no deal and calls a referendum, giving the British people the chance to say whether they really want to proceed with this Brexit, which doesn't meet any of the promises that were made three years ago, or if we're better off staying.
"The likelihood is we will end up with a referendum."