David Cameron backed out of a late bid to get Angela Merkel to back a plan to let Britain curb immigration, according to his former communications director

Panicking David Cameron aborted plans to make a last-ditch plea to Angela Merkel over letting Britain curb immigration just ten days before his EU referendum defeat.

He arranged a dramatic phone call to the German Chancellor to ask her to back him – but changed his mind moments before speaking to her because it would look ‘desperate’.

And Cameron was warned by his right-hand man at No 10 that exaggerating the economic risks of leaving the EU was ‘driving voters into the arms’ of Brexit campaigners.

The claims are made in a bombshell book by Sir Craig Oliver, Cameron’s director of communications, who says Cameron lost because his claim to have fulfilled his vow to win concessions on migrant numbers was ‘widely ridiculed’.

The disclosures sparked a major controversy at the Conservative conference which opened in Birmingham yesterday, where Theresa May faced calls to speed up Brexit talks with the EU.

Oliver salutes George Osborne’s loyalty to Cameron, saying he ‘sacrificed himself’ for the former PM.

But the then Chancellor’s emergency Brexit Budget ‘went down like a cup of cold sick’ with Tory MPs.

It left Cameron facing a ‘nightmare’ as ‘MPs stuck the knife in’. Osborne refused to drop negative tactics – dubbed Project Fear by critics – saying they must ‘keep punching the bruise’.

Last night, pro-Brexit Tory MP Jacob Rees-Mogg said of the aborted Merkel plan: ‘Mr Cameron achieved thin gruel in the talks because he was too scared to ask for roast beef.

'Sadly, it appears that when it came to getting a last-minute vow from Mrs Merkel, he bottled it.’

Oliver recounts how ten days before the referendum, he told Cameron they had lost the argument on immigration.

He urged him to declare he had ‘listened’ to voters’ concerns and would win new curbs on immigration AND stay in the EU.

Sir Craig Oliver, pictured with rumoured girlfriend and Remain campaigner Lucy Thomas, has written a bombshell book around the referendum campaign

Cameron said, ‘Spot on’, and set up a phone call to Merkel to get her to make an 11th hour intervention.

But after discussing it with Osborne, the pair decided it was a ‘fool’s errand’.

They had spent the whole campaign arguing the economic risk of quitting the EU ‘trumps immigration’.

They weren’t so sure now – but it was too late to switch. The Merkel call was ‘pointless’ even if she agreed: it would ‘look desperate’.

When she came on the line, Cameron said ‘this was not the moment to ask for more’ on immigration after all.

A similar U-turn days before the Scottish referendum helped Cameron win, with major concessions handed to the Scots.

The Government’s response to new evidence of rising immigration was ‘like a sticking plaster on a gaping wound’, says Oliver.

Cameron and Osborne denied their pro-EU campaign was Project Fear.

But Oliver reveals he warned Cameron that ‘hyperbolic’ claims about economic doom outside the EU were ‘driving voters into the arms’ of the Brexiteers.

The book also reopens the row over Osborne’s Brexit Budget threat. Oliver said it proposed ‘horrific solutions’.

Sir Craig claims Mr Cameron, right, backed out of the last-ditch plan just second before he was due to speak to Ms Merkel, left

But aggressive Osborne insisted Remainers should keep ‘punching the bruise’.

Cameron complained in the New Year that the EU’s ‘hopeless’ renegotiation offer left him facing a ‘car crash’.

After the defeat, angry Cameron told a ‘squeamish’ Merkel he could have won if she had backed him on immigration. But she said she had no regrets.

Oliver says Cameron effectively sealed his own fate in 2014 when he said he ‘would not take no for an answer’ on a significant cut in EU migrants.

‘Our claim that we had been true to that statement was not accepted and was widely ridiculed.’

Brexit Secretary David Davis will today pledge to introduce a ‘Great Repeal Bill’ to turn all EU laws into British legislation on the day of our exit.