The Prime Minister argued that the wealth generated by the UK capital’s status as a financial centre benefited Scotland and would be lost if there is a Yes vote on 18 September.
Visiting Dumfriesshire, Mr Cameron attempted to counter Alex Salmond’s argument that London’s economic dominance is at the expense of the rest of the UK.
“Alex Salmond is making an extraordinary argument,” Mr Cameron told ITV Border. “London is an enormous and precious asset for the whole of the UK, and many Scots benefit from London’s hub status and from working and investing in London, and from the investment from London into Scotland.
“Now, surely we should be making the most out of that connectivity rather than separating ourselves from it.
“People in Scotland say to me, ‘I’ve got children working or studying in London’, and people in London say to me, ‘I’ve got children working or studying in Scotland’.
“Do we really want to have a situation where they are working or studying in a foreign country?
“We don’t want that so let’s not vote for it – let’s vote to keep the UK together.”
Earlier this year at a New Statesman lecture in London, Mr Salmond quoted the LSE economist Professor Tony Travers when he described London as the “dark star of the economy, inexorably sucking in resources, people and energy” from the rest of the UK.
During his lecture, Mr Salmond argued that Scottish independence would provide “a northern light” to rebalance the economy of the British Isles.
Mr Cameron’s defence of London was disputed by Mr Salmond’s supporters, who also took issue with the Prime Minister’s claim that an independent Scotland would become a foreign country.
Jamie Hepburn, the SNP MSP who sits on Holyrood’s finance committee said: “Mr Cameron’s comments about London show just how out of touch he is.
“It is widely accepted that Westminster’s focus on London has grossly unbalanced the UK economy and distribution of wealth – and independence will help rebalance the economic centre of gravity across these islands. An independent Scotland and the rest of the UK will be the closest of friends and neighbours, on the basis of equality of status – just as the UK has never defined the Irish Republic as a foreign country.”
In Dumfriesshire, Mr Cameron visited the Lockerbie ice rink, where he once again refused to take part in a TV debate with Mr Alex Salmond.
He also angered the SNP by claiming that Mark Carney, the Governor of the Bank of England, had suggested that leaving the United Kingdom would mean losing the pound.
The Prime Minister said: “The head of the UK Treasury and the Governor of the Bank of England have been clear that, for Scotland, you keep the pound as part of the UK, but if you leave the UK you lose the pound.
“I’m pretty clear about when a Governor of the Bank of England says difficult – I’ll leave him to speak for himself – but the argument I am putting is that Scotland keeps the pound inside of the UK but doesn’t outside of the UK.
“That is not simply the view of the political leaders in the Labour, Liberal Democrat and Conservative parties, it’s also the view of experts who have been advising us.”
But Mr Hepburn referred to a Bank of England statement, which said that Mr Carney did “not pass judgment on the relative merits of the different currency options for an independent Scotland” when he came to Scotland earlier this year.
In Edinburgh in January, Mr Carney did say, however, that a successful currency union would require “some ceding of national sovereignty” by Scotland.
Mr Hepburn claimed that Mr Cameron was attempting to “misrepresent Mark Carney” and it showed “that the No camp has lost the argument on the currency union and desperation has set in”.
He said: “The Governor of the Bank of England made clear that the Bank ‘would implement whatever monetary arrangements were put in place’ between the Scottish and UK governments.
“David Cameron drops clangers every time he visits Scotland and he is still too scared to debate [with] the First Minister.
“This latest gaffe is embarrassing on a number of levels. It is absolutely unacceptable to misrepresent Mark Carney’s views in order to make anti-independence points, and this comes just weeks after a senior Labour figure argued against involving the Governor in political debates.
“David Cameron – who looks now to have replaced Alistair Darling as the head of the No campaign – must take responsibility for this and apologise to Mark Carney and to the people of Scotland for spreading misinformation.”