But Sir John’s extraordinary intervention was blasted by respected Tory backbencher and committed eurosceptic Jacob Rees-Mogg.
The North East Somerset MP told Radio 4’s Westminster Hour: “What we’ve had today are the bitter ramblings of a vengeful man.
“He is the man who took us into the Exchange Rate Mechanism, destroyed hundreds of thousands of jobs, had people evicted from their homes and led to the destruction of businesses for the sake of his failed European policy.
“And now he says things that are both hypocritical and untrue in his attack on Boris.
“And how magnanimous Boris was in saying we should rise above it; well, I’m going to sling the mud straight back at Sir John Major, a knight of the garter who ought to know how to behave better.