DOWNING St has brushed aside Nicola Sturgeon’s warning about promoting the Remain campaign’s argument in “fear-based campaigning” as David Cameron echoed Gordon Brown and said voting to stay in the European Union was the “patriotic” thing to do.

The Prime Minister is travelling to the G7 summit in Japan where he will hope to get yet more endorsements from international leaders for his bid to keep Britain in the EU.

Although the EU is not formally on the agenda, UK Government officials said it would be raised “in the margins” and possibly at bilaterals with counterparts. Mr Cameron might also be hoping a line or two about the importance of Britain remaining in the EU makes it into the final summit communique.

On Monday, the First Minister ticked off Chancellor George Osborne for making overblown claims, saying: “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.”

But when asked if the Prime Minister agreed with Ms Sturgeon’s warning, his spokesman said: “The Government is clear that people are asking for facts. It is right to set out the best assessment based on the most comprehensive analysis of what the economic impact is of the Out vote to leave the EU.

“But it is also a positive case because the Treasury has also assessed that there is a potential economic upside from remaining in the EU. The reform package negotiated by the PM, the Treasury assessed, could be worth up to four per cent of GDP as a result of, for example, completing the digital single market and completing the market for services.”

When it was suggested the Treasury figures were not facts but predictions, the spokesman replied: “These are forecasts, assessments of the scenarios that have been described by the former deputy Governor of the Bank of England as reasonable based on the best available tools.”

At another campaign event in Luton, Mr Cameron declared: “The big bold patriotic thing is to stay in the fight for the world we want.”

Last month, Mr Brown claimed he was making the “positive, principled, patriotic case” for Britain to stay in the EU.

The Tory leader also addressed growing resentment among some of his anti-EU colleagues, who are alarmed at what they have dubbed the Treasury’s “dodgy dossier”, which warned Brexit would plunge the UK into a year-long recession and cost up to 820,000 jobs.

Conservative MPs - one of whom, Marcus Fysh, called the Treasury dossier "specious b******s" – are said to be planning a vote of no-confidence in their party leader following the referendum vote.

The PM acknowledged, given the passions involved over the EU, there was always going to be strong arguments but added: “Do I believe at the end of this we can all come together and accept the result? Absolutely, I do.”

Addressing workers at the Luton HQ of low-cost airline easyJet, Mr Cameron drew on the Treasury analysis, which claimed that, based on a 12 per cent slump in the value of the pound following a Brexit vote, £230 would be put on the cost of a family holiday and £4 on the price of a phone call home.

“There are some very strong retail arguments about the cost of a holiday, the cost of food, the cost of using your phone, for staying in the European Union," declared the PM.

But Steve Hilton, Mr Cameron's former policy guru, who backs Brexit, said the holiday price warning was another example of the sort of "pathetic, patronising EU scares" being deployed by both sides.

Vote Leave chief executive Matthew Elliott claimed it was remarkable to see the PM “talking down our country and our economy day after day”.

He said: "Yesterday, Nicola Sturgeon pleaded with the Government to stop the negative campaigning and urged them to stop making exaggerated claims that insult the public's intelligence. Clearly, they're not listening.”