Jeremy Corbyn was simply waiting to see what Theresa May did before deciding whether to attend last night, according to the BBC's former economics editor Paul Mason.
Corbyn decided to take part last night just a few hours beforehand, in what was widely perceived as a last-minute u-turn.
However Mason said: "I’m not sure he did change his decision... you’ve got to play clever in these things
"I think it’s more like [Labour] thought 'lets see how the land lies'."
He believes that Caroline Lucas was the winner of the debate as he gave Amber Rudd a "walloping", but added that Corbyn couldn't do that as he needs to look Prime Ministerial.
Turning to the loser, Mason thought UKIP really came off worse and suggested the party is "folding" for the Tories.
Listen to the full interview above