PRIME MINISTER Theresa May’s Brexit negotiation skills were scorned yesterday after a row over the size of Britain’s severance bill.

The European Commission’s chief negotiator Michel Barnier refused to be drawn on reports that the bill could be as large as €100 billion (£84.5bn).

However, he insisted that there must be a “settling of accounts” and that it was an “illusion” to think the process of Britain leaving the EU would be quick and painless.

Labour leader Jeremy Corbyn said the €100bn figure was probably the EU’s “opening gambit” in the negotiations.

During an election visit to Bedford, Mr Corbyn said: “I’ve no idea where this figure comes from, and I suspect they haven’t got an idea either.

Mr Corbyn called on the PM to take a more sensible and serious approach to the negotiations, focusing on a trade deal — but also protecting the rights of workers, consumers and the environment.

Shadow foreign secretary Emily Thornberry said Ms May’s negotiating skills were reminiscent of Charlie and the Chocolate Factory’s spoilt and immature Veruca Salt.

Speaking on Channel 4 news, she said: “The truth is that Theresa May paints herself as ‘a bloody difficult woman’ or a Margaret Thatcher figure; but I think this is less Margaret Thatcher and more Veruca Salt.

“You can’t just stand there and simply say: ‘I want, I want, I want,’ when you are negotiating.”

Ms Thornberry warned that if Ms May continued being obnoxious, she would not be able to secure a deal.

Brexit Secretary David Davis insisted: “We will not be paying €100bn.”