DEPENDING on your view, London is either the dark star that sucks the lifeblood from the rest of the country or the golden citadel that is the gateway to Britain.

At an independence debate this week, an audience of some 1000 people crammed into the City's Guildhall and was asked: does Scotland need London and does London need Scotland; code for Yes or No to independence?

The response from the UK capital, whose citizens include some 100,000 Scots, was overwhelmingly for keeping Scotland in the Union. The issue of London was raised a few months back by Vince Cable. The Business Secretary complained the Big Smoke was becoming a "kind of giant suction machine, draining the life out of the rest of the country".

In March, Alex Salmond took up the theme, likening London to the "dark star of the economy, inexorably sucking in resources, people and energy" from the rest of the UK and gushed how an independent Scotland would become "a northern light" to rebalance the economy.

Last month, George Osborne popped up in the provinces to decry how the London powerhouse was dominating the economy and this, he concluded, was "not healthy for our economy". The Chancellor's solution: a "northern powerhouse" linking cities such as Manchester and Leeds via a new HS3 rail link, effectively creating a global city across the Pennines. One found it hard to disagree with that other northern powerhouse, Lord Prescott, when he growled: "This is more about northern votes than northern growth."

On Thursday, Ed Miliband followed suit, promising a Labour government would devolve £30bn from London to the cities, which he wanted to link up to create regional economic powerhouses to rival the capital in creating jobs.

Coincidentally, David Cameron landed in Scotland to be nice to Glasgow with a £500m City Deal; nothing, of course, to do with the referendum. Now, it might be, after the Ukip earthquake, that both Labour and the Tories have realised voters in the English northern cities and regions could be key to who enters Downing St next year.

There might also be a fear that, if the Union were secured in the September referendum, the 2015 General Election result might underline just how disunited the UK has become between a Labour-dominated north and a Conservative-dominated south.

Decentralisation is the buzzword, with more powers promised for Scotland and northern England. Yet London, like all global cities, will always attract a disproportionate number of jobs and investment projects. A few months back, Boris Johnson sought to dispel what he termed one of the "myths of our time", that London was drifting apart from the rest of the UK "like some lunar module about to detach itself while the rest of the rocket slumps back to earth".

London, the Mayor insisted, was "the capital of England, of Britain, of the UK, and it is profoundly in the interests of all those political entities that it should remain so". We will know soon enough whether Scotland will detach itself from the mother ship and begin its own independent journey through time and space.