House prices across the UK are up by 9.5% annually – but in London, by 18.2%.

The finding, from Nationwide, has left agents in the capital unsurprised.

Peter Rollings, CEO at Marsh & Parsons, said: “In south-west London, we have 48 potential buyers registered for each available property.

“A two-bedroom, ground-floor flat in Balham, initially advertised at £450,000, recently attracted 107 viewings and 53 offers. It eventually sold for £549,000.”

According to Nationwide, reporting on March, monthly house price growth across the UK was 0.4%, bringing the average house price to £180,264 – 3% below the 2007 peak.

In London, the average house price is £362,699 – more than twice the level in the rest of the UK when London is excluded.

Nationwide economist Robert Gardner said: “The gap between house prices in London and the rest of the UK is the widest it has ever been.”

England’s lowest house prices are in the north, where they average £119,702, but even that is 5.9% up on a year ago.

In the south-east outside London, house prices have bounced up 10.1% in the last year.

Meanwhile, the Financial Conduct Authority has warned that rising house prices are “posing the most significant” risk to the UK’s economy.

It said: “Elevated prices could lead to mortgage affordability stretch, particularly when interest rates start to rise, and increases the possibility of price correction in the future if prices are unsustainable over the long-term, given the prospects for income growth and rising levels of debt seen in the UK.

“Risks to consumer protection may grow if stronger housing market activity is accompanied by further substantial and rapid increases in house prices and a further build-up in household indebtedness, which is already elevated for some households.”

An estimated two in three house purchases are made with a mortgage.