The former Prime Minister’s latest intervention on the Brussels divorce proceedings comes in the form of an article posted online.

Writing on his own website Blair said 2018 was the year that “the fate of Brexit and thus of Britain will be decided”.

He said: “Open up the dialogue with European leaders about reforming Europe, a dialogue they're more than willing to have now because they realise Brexit also damages Europe economically and politically.”

Blair, who was UK leader between 1997 and 2007, told his successor to infuriate the divorce process by refusing to vote with the Government in the House of Commons, even though it would be defying the will of the people who voted in the June 2016 referendum.

He said: “Make Brexit the Tory Brexit. Make them own it 100 per cent.

“If Labour continues to go along with Brexit and insists on leaving the Single Market, the handmaiden of Brexit will have been the timidity of Labour.”

So far Labour has whipped its MPs to vote for the triggering of Article 50 to begin the divorce process and has abstained on votes in Parliament for more technical details on leaving the EU.

The party’s official position so far has been to respect the result of the referendum and to leave the single market.

However, Blair, who famously called for the UK to join the Euro in the early 2000s, has said the party must change its position.

He added: “I would like the Labour Party to be on the high ground of progressive politics, explaining why membership of the European Union is right as a matter of principle, for profound political as well as economic reasons.

“I disagree with our present position strategically.”

In another part of his war cry on Brexit Blair said: “At every PMQs nail each myth of the Brexit campaign, say why the Tory divisions are weakening our country - something only credible if we are opposed to Brexit not advocating a different Brexit, and challenge the whole farce head on of a Prime Minister leading our nation in a direction which even today she can't bring herself to say she would vote for.”

When quizzed on LBC radio in October Mrs May, who voted remain in 2016, refused to say she would support Brexit second time around.

Presenter Iain Dale asked the questioned several times to the Prime Minister, who simply insisted she will be delivering the will of the people and taking Britain out of the EU by March 2019.

She said: “Well, I don’t answer hypothetical questions.”

Blair’s article has been attacked by campaigners of Brexit for ignoring the will of the British people.

Richard Tice, who helped found one of the two Leave campaign groups, said: “Blair and his elitist gang are damaging our negotiating strength, thus damaging our national interest by their continuing efforts to undermine democracy.

“History will not forgive them.”