Ruth Davidson and Boris Johnson clash in EU debate

The Scottish Tory leader put on a pugnacious display in the final set-piece television debate and went on the attack against two members of her own party, accusing them of lying over Turkish accession to the EU and having no plan to reduce migration.

Returning fire on his Remain opponents, Mr Johnson said they had claimed they would “come here with a positive case, but they’re back to Project Fear.”

In front of a boisterous 6,000-strong crowd at the Wembley Arena in London that did not hold back from heckling and cheering their side, the former London mayor received the largest ovation of the night when he said tomorrow’s referendum vote could be “our country’s independence day”.

As a bad-tempered two month referendum campaign enters its final phase, the five men and women who have held the office of First Minister of Scotland will today tell voters: “The stakes could hardly be higher.”

Nicola Sturgeon, Alex Salmond, Jack McConnell, Henry McLeish and Jim Wallace will make an appeal for voters to back Scotland’s continued membership of the EU in what they will call an “unprecedented display of unity in the history of the Scottish Parliament”.

However there was little unity on display last night, with no holds barred blue-on-blue and red-on-red attacks. Ms Davidson warned voters against taking the risk of backing Brexit, saying “You have to know, or don’t go.” On immigration, she said the Leave campaign “Have a slogan, they have a poster, but they don’t have a plan.”

“This isn’t the Boris show,” she heckled Mr Johnson as he told the audience that EU membership prevented the export of haggis. Taunting Mr Johnson with his previous comments that Turkish membership of the EU “isn’t on the cards”, she later turned to the audience, saying “you deserve the truth, you deserve the truth.”

And she said the UK needed to have “a much bigger conversation than this” about migration as fellow Remain panellist, the TUC general secretary Frances O’Grady, challenged the Leave campaign to say how many people would be allowed into the UK after Brexit.

The strongest attack of the night came from Sadiq Khan, the Labour mayor of London, who alluded to debate over the rhetoric on immigration in the referendum, telling Mr Johnson: “Your campaign hasn’t been Project Fear as far as immigration is concerned. It’s been Project Hate”

Mr Khan was backed by the SNP minister Humza Yousaf, who said during the broadcast in a break from the debate that a controversial poster unveiled by Nigel Farage was “xenophobic and borderline racist”.

Mr Johnson said it would be an “act of economic self harm” to remain in a union that he said was a “job-destroying engine”. He dismissed as “extraordinary” claims that other European countries would impose tariffs on British manufacturers following a UK exit from the EU.

Alongside him, Labour MP Gisela Stewart appealed to voters to “take back control”, telling them: “Sometimes voting doesn’t really make much difference. On Thursday, it really does.”

She was joined by Tory energy minister Andrea Leadsom, who said the 28 member states of the EU “cannot even organise a takeaway curry”, let alone organise free-trade deals with other world economies.

On a day politicians faced off in the shadow of the English national football stadium, David Beckham said he was voting in favour of remaining in the EU because “we should be facing the problems of the world together and not alone”.

His comments came as fellow former England footballer one-time Celtic manager John Barnes was forced to clarify he was also in favour of staying in the EU, after Michael Gove said in a radio interview that he was pro-Brexit.

Last night the Prime Minister gave the clearest signal yet that Mr Johnson would be welcomed into the Cabinet in an attempt to heal rifts within the Tories over the EU campaign.

In an interview with ITV News, he said he wanted “star players” like Mr Johnson to join the government after the EU vote, regardless of the result. He admitted the campaign had been “difficult” for the Tories, and said he would “accept the verdict of the British people” on Friday.

The Prime Minister denied he had taken a gamble by calling the referendum, saying he was “not a risk taker”.

“I know we have to settle this issue. I think there are some decisions that are so big we should ask the people and not the politicians to make them,” he said.

Mr Gove said the Remain campaign would return any money from “tainted sources” after it emerged a member of the British National Party (BNP) had donated £600,000.

He said that he was not aware that Gladys Bramall appeared on a leaked BNP membership list from 2006.