General Election 2015: Tony Blair attacks David Cameron's weak plan for EU referendum

The former Prime Minister will condemn Cameron’s 'sop' to the right of his party by offering a referendum on Britain’s membership of the EU

Tony Blair makes a rare supportive intervention for Ed Miliband today (Getty Images)

David Cameron’s European policy risks triggering the “most intense period of instability” in Britain since the Second World War, jeopardising jobs, prosperity and the country’s influence in the world, Tony Blair will warn today.

In his first intervention in the election campaign the former Labour Prime Minister will condemn Mr Cameron’s “sop” to the right of his party and parts of the media by offering a referendum on Britain’s membership of the EU.

Mr Blair is markedly warmer to Ed Miliband than he was last year, when he warned that Labour risked running a campaign “in which a traditional left-wing party competes with a traditional right-wing party, with the traditional result.”

Mr Blair praises Mr Miliband’s “convictions” both on Europe and other issues, which he says show a determination to follow his principles “even when they go against the tide”. “I respect that,” he adds.

In contrast he accuses Mr Cameron of trying to appease anti-European groups that threaten to cause “chaos” for investment and jobs.

“The oddest thing of all about David Cameron’s position [is that the] Prime Minister doesn’t really believe we should leave Europe; not even the Europe as it is today,” he is expected to say.

“This was a concession to Party, a manoeuvre to access some of the UKIP vote, a sop to the rampant anti-Europe feeling of parts of the media.

“It is greatly to Ed Miliband’s credit that he resolutely refused to make that trade.”

He said Mr Miliband too had faced calls from the media and “many inside our Party” to make a similar pledge, but had shown “real leadership” by rejecting such pressure.

“He showed that he would put the interests of the country first. He showed that on this, as on other issues, he is his own man, with his own convictions and determined to follow them even when they go against the tide. I respect that.”

Labour ministers hope Mr Blair’s comments will resonate with soft Tory voters who previously supported the Party but feel it has moved too far to the left under Mr Miliband.

By picking on Europe – an issue on which both Mr Blair and Mr Miliband agree – strategists hope to reinforce the message that the greatest danger to Britain’s economic prosperity lies with the Conservatives, not Labour.

“The Tory campaign talks of chaos should Labour win. Think of the chaos produced by the possibility, never mind the reality, of Britain quitting Europe,” Mr Blair will say.

“Jobs that are secure suddenly insecure; investment decisions postponed or cancelled; a pall of unpredictability hanging over the British economy.”

Discussing the consequences if Britain votes to leave the EU, he will say: “There is a complete under-estimation of the short-term pain of negotiating exit.”

“Should the vote go the way of exit, then there would be the most intense period of business anxiety, reconsideration of options and instability since the war.

Tony Blair has praises Ed Miliband’s “convictions”, which he says show a determination to follow his principles (Getty) (Getty Images)

Mr Blair will deliver his speech in his former constituency in Sedgefield. He will be joined by his wife Cherie and Phil Wilson, his successor as Labour MP.

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