Tony Blair today said the Tories are on course for re-election as he called on Britain to reject a Brexit delivered “at any cost”.

He showered praise on Labour MPs and candidates but said Theresa May is set to achieve a “large majority” as he continued his war on a hard Brexit.

Blair, who won three general elections, spoke out 24 hours after Jeremy Corbyn launched his campaign with a pledge to take on the “establishment” and the leader’s officials confirmed the party would rule out a second referendum.

Today, however, Blair used a newspaper article to warn over a Tory “landslide” which would allow May to pull Britain out of the EU even if she fails to negotiate a deal.

“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,” Blair wrote in the London Evening Standard.

“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.”

Blair has repeatedly pleaded with serving MPs to leave the door open to reconsidering Britain’s exit from the EU.

Now he has described May as a “reasonable person pursuing an unreasonable policy”.

“Her current position is: Brexit will happen, there’s no turning back and no deal is better than a bad deal. What for her is non-negotiable, is that Brexit will not happen.

“Therefore she wants a landslide majority so that there are sufficient numbers of Tory MPs who will vote to leave Europe even if the deal does not deliver ‘exactly the same benefits’ as membership of the single market and customs union. Or there is no deal.

“The Daily Mail front page ‘Crush the Saboteurs’ tells you exactly what the aim of the election is — and the saboteurs it has in mind are not, I think we can safely say, the Tory Right. ”

Labour has not yet said what role Blair will play in the party’s election campaign.