Britain’s capital city is becoming a spoiled brat. It is stupendously rich. It sucks population out of the rest of the country and then whinges when this drives up house prices. Now at Christmas, it demands the kind of baubles you would expect of an Arab princeling or a banana republic.

London this month stamped its foot and got the government to give it £5m for a “study” – yes, for a study – into how it needed more concert halls to boost the ego of a conductor, Sir Simon Rattle, who wants a new £278m concert hall of his own. This is despite £111m spent between 2005 and 2007 turning the Royal Festival Hall into “the best in the world”.

Without the new hall, Rattle would throw a tantrum and then we’d be sorry. That is how you spend public money in London. Weep, Barnsley, weep.

Meanwhile, up the road, the actor Joanna Lumley wants a different bauble. She wants a garden bridge over the Thames at £100m and rising. Rumour has it that London’s mayor, Boris Johnson, and chancellor George Osborne were in a dinner party bidding war over who would give more, ending with each pledging £30m – of other people’s money. Lumley is lucky her bridge is not over the Tyne.

Meanwhile out in Stratford, east London, West Ham United football club want a new ground. Osborne says, name your price. He has duly spent in the region of £700m to refashion his Olympic “legacy” for West Ham’s private benefit. Eat your heart out, Aston Villa.

The truth is whatever London wants, it gets. The reason is that the purse-strings are held by Londoners. London businessmen want a third airport. They must have it, somewhere. Cyclists want a “superhighway”. They get it.

Crossrail’s staggering £15bn cost was so easily found that Crossrail 2 has decided to cost itself at £27bn. Should any other part of the kingdom ask for such sums it would be laughed out of court.

It is London not the provinces that is drunkenly dependent on public money. The latest figure for infrastructure spending on each Londoner is £5,500 a year, against Yorkshire’s £580 a head and the north-east’s £220. Not surprisingly, in the last three years London has grown three times faster than the north. Between 2010 and 2012 the capital added 216,000 more private sector jobs while Bradford, Blackpool and even Glasgow lost them. Vince Cable was right in calling London “a giant suction machine draining the life out of the rest of the country”.

This cannot be in the capital’s interest. Walk around parts of north Manchester, South Yorkshire or Teesside and you could still be in cold war eastern Europe. These places are economically destitute, dependent on taxes paid overwhelmingly in London and the south-east. By keeping them deprived, London keeps them parasitic and in its pay. Yet the capital never stops lobbying for more public money directed at its own interests.

High-speed rail, which every study shows benefits the richer end of a line, will help London rather than Birmingham or Manchester. The same goes for the sums poured into London’s university sector, a spending magnet that has no need to be in the capital.

The same applies to culture. Cut an opera grant, a BBC channel or a London sports facility and all hell breaks loose. The Treasury is terrified of the London museums lobby, excusing them from charging for entry (Tate London is free, Tate St Ives is £6). In the recent autumn statement arts in London were specially excused cuts. Local museums may close across Lancashire, but not in London.

It must be time for the capital to lift its snout from the Treasury trough and allow room for those less fortunate than itself. It should accept that all public sector jobs not essential to London be moved out of town. It should plead for new transport investment to be between regional centres, not into London. It should argue that housebuying subsidies should end, and money be concentrated on the poor.

London should accept a mass migration of state-funded higher education out of the metropolitan. The mayor of Middlesbrough once told me the best thing for his city was the arrival of a university. Dispersing hundreds of thousands of students out of the capital would energise provincial England, and free the capital’s rental market. London would not suffer.

As for the arts, London’s are bloated and indigestible. You can hardly get a ticket for a West End play. Every show is booming. My local cinema is being converted to a live theatre. The spotlight of public money should turn on Bristol, Birmingham, Leeds and Manchester. If the BBC can relocate to Salford, so can a London orchestra.

The artworks hoarded in the basements of London galleries and museums should be distributed to public museums across the country. Why should Wright of Derby’s great painting of Brooke Boothby not hang in Lichfield cathedral, which he helped rebuild, rather than languish in a Tate vault? Art that belongs to the nation belongs to the nation. It is not the private property of a group of London curators.

The capital does not need more bridges, concert halls, railways, football grounds, galleries or artworks. They should be shared. The city claims to be the richest and most exciting on Earth, in which case it can show magnanimity. Besides, it’s Christmas.