The phrase echoes an argument by Labour's Aneurin Bevan - one of Mr Corbyn's heroes - against unilateral nuclear disarmament in 1957.
I presume you have the figures?
EB: You're holding your manifesto, you're flicking through it, you've got an iPad, you've had a phone call while you're in here and you don't know how much it is going to cost.
JC: Can I give you the exact figure in a moment?
"We gave people the choice, and the British people made a decision to leave the European Union, and I think it's important for them to see their politicians delivering on that choice and respecting the will of the people", May told Paxman.
Ms Barnett said: "It's actually Angela Rayner, your shadow education secretary - £2.7 billion and then £4.8 billion plus that with half a billion to reverse the cuts to the Sure Start scheme".
Mr Corbyn said: "This will mean that all of our children will get the chance to go to nursery, to go to pre-school and to develop socially with each other".
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Mr Corbyn appealed to another audience member from a "salt of the earth" Labour family to "think again" after he could not vote for "ruthless" policies that would damage his small business, such as the abolition of zero hours contracts and the imposition of a £10 minimum wage.
Labour intends to end means-testing of free childcare for two-year-olds and to extend the 30-hours-a-week provision to all three and four-year-olds, not just those whose parents are in work.
Asked if those numbers "sound about right", Corbyn responded "it does sound correct".
He wasn't drawn into discussing resignations, instead insisting that he would win the election.
"I only have to lose six seats in this election for that to happen".
"His interview with Mr Corbyn was a nightmare - and not for the Labour leader" - Telegraph sketch writer Michael Deacon on rottweiler-turned "tired old dog" Jeremy Paxman.
Lib Dems were quick to react to the radio appearance.
Jeremy Corbyn faced lengthy questioning on foreign policy and security, defending his claim that the killing of Osama bin Laden was a "tragedy" because the al-Qaeda chief should have been put on trial. It seems he's been borrowing Diane Abbott's calculator.
The second most popular, with just over a thousand retweets, was a viewer quoting Jeremy Paxman, who said European Union negotiators might think Theresa May was a "blow-hard who collapses at the first sign of gunfire".