Tony Blair has predicted Theresa May will win a "large majority" in the UK general election but called for a "movement" of pro-EU voters to prevent her getting a mandate for a "Brexit at any cost".

The former prime minister said the opinion polls, which put Labour as many as 24 points behind the Tories, "appear to be definitive" in pointing towards a big Tory victory on June 8.

But he called for a "movement of informed voters" to demand candidates make clear whether they would support the UK leaving the European Union with no deal, or one that does not give good access to the single market.

A failure to do so would give Mrs May, who has said "no deal is better than a bad deal", a "free hand" to pursue a "Brexit at any cost", with no option for the UK to change its mind about leaving the EU if the exit terms are unpalatable.

"Whatever may be desirable, the polls appear to be definitive on the election and the respective polling positions of the leaders of the government and opposition," he said.

"There are many great Labour candidates and MPs and I will be fully supportive of them. But the fact is that if the polls are right, Theresa May will be PM on June 9 with a large majority. But with what mandate?

"Unless there is some clarity around that mandate, a re-elected Tory government could do what it wants. The PM says she wants her hand strengthened in the Brexit negotiations... what she really wants is a free hand - but to do what?"

Mr Blair also said that the Daily Mail's 'Crush the saboteurs' headline the day after Mrs May called the election revealed her true intentions.

PA Media