Nicola Sturgeon warns George Osborne: fear-based EU campaigning could have negative effect on voters

The First Minister suggested the Treasury was overstating its case with a warning that Brexit could see the UK losing up to 820,000 jobs.

Asked if Mr Osborne’s continued warnings of economic doom could alienate voters, Ms Sturgeon replied: “You only have to look at the Scottish referendum to know that that kind of fear-based campaigning, that starts to insult people’s intelligence, can have a negative effect.”

The FM, who visited Westminster to present what she called a positive, progressive pro-EU front with Plaid Cymru’s Leanne Wood and the Green Party’s Caroline Lucas, said it was always better to seek to enthuse and inspire people rather than to frighten them.

She went on: “People have got the savvy to see through some of the overblown claims. Of course, there would be an economic impact, short, medium and long term if there was a vote to leave the EU but I’m much more interested in the positive reasons to stay in the EU; being part of the single market, the investment and jobs that come with that.

“But also for me what is particularly important are the social and employment protections, maternity rights, paid holidays, a whole range of health and safety protections. These are better guaranteed by being part of the EU than they would be if a Westminster government had unfettered control over them,” added Ms Sturgeon.

Scottish Vote Leave welcomed her comments. Tom Harris, its director, said: “David Cameron calls remain a 'positive campaign' but we in Scotland know it's just Protect Fear. Even supporters of a Remain vote are saying it.”

The FM’s criticism of Treasury fearmongering came as the Whitehall department put out another warning; this time that Brexit could increase the cost of family holidays by hundreds of pounds and make travel more expensive.

This follows an earlier message from David Cameron and the Chancellor that Brexit was the “self-destruct option”, which would lead to a yearlong “DIY recession”.

According to a worst-case "severe shock" scenario put forward by the Treasury, a UK exit could result in six per cent lower GDP over two years, the loss of 820,000 jobs, a four per cent fall in average incomes, a 15 per cent collapse in the value of the pound and £39bn added to government borrowing.

The Prime Minister said: “The economic case is the moral case. The moral case for keeping parents in work, firms in business, the pound in health, Britain in credit, the moral case for providing economic opportunity rather than unemployment for the next generation. Where is the morality in putting any of that at risk for some unknown end?”

But the Vote Leave camp dismissed Mr Cameron’s latest warnings as more desperate scaremongering.

Leading Outer Boris Johnson noted how the Treasury’s worst case scenario for Brexit was bleaker than the Great Depression of the 1930s, pointing out the Treasury had been "hopelessly wrong" in previous forecasts, including its support for the Exchange Rate Mechanism in the early 1990s.

Fellow Brexiteer, Iain Duncan Smith, said the Whitehall analysis was biased and dishonest; he accused the Government of "misusing its power and misusing the civil service".

Meantime, Labour’s John McDonnell said the Treasury analysis was “more evidence that a Tory Brexit would only make matters worse for working people already struggling under a Tory Government” and what was needed was a Labour administration committed to investment to build a high-tech, high wage economy of the future.

Today, his colleague Harriet Harman, the party's former deputy leader, will call on Ofcom, the media regulator, to ensure more women are heard in the In-Out debate.

She will say: “Women are being excluded and the debate narrowed. The broadcasters have a legal duty to keep a balance between those who want remain and those who want to leave. They should have a balance between men and women. This referendum is too important to be left to men.”