Matthew Goodwin, co-author of Brexit: Why Britain voted to leave the European Union, said he'd eat his book if Labour polled higher than 38 per cent under Corbyn's leadership.

And unfortunately for Goodwin, Labour won 40.3 per cent of the vote.

As a result, people got a little overexcited telling him to "eat his book".

In fact, he couldn't really say anything on Twitter without lots of people telling him to "eat his book".

Well, he just ate his book live on Sky.

Goodwin also donated his contribution fee for appearing on the channel to the Motor Neurone Association.

A man of his word, he ate the book.

You can watch the clip here.

In 2015, former Lib Dem leader Paddy Ashdown said he'd 'eat his hat' if the exit poll was right (and it was).

As YouGov's Joe Twyman puts it: "Never promise to eat inedible items".