Voters fall off London's housing ladder as super-rich leave property empty

London property: gold bullion in the sky, according to Boris Johnson, the city's mayor. Photograph: Belinda Lawley for the Guardian

London's most desirable housing enclaves are haemorrhaging voters, according to figures fuelling fears that foreign buyers are turning primeproperty into vacant investment assets.

More than 2,000 voters have disappeared from five wards in Westminster in the past 12 years, according to electoral registration data published this week.

The biggest fall has been in Knightsbridge and Belgravia, where there are now 11% fewer voters than in 2002. In the West End ward, which covers Mayfair and Soho, there are 498 fewer registered voters, a drop of 7%. There have been 5% falls in Abbey Road and Bayswater and a 4% fall in the area around Marylebone High Street.

As only UK, European Union or Commonwealth citizens can register to vote, the registration data is being seen as evidence that investors from east Asia – especially China – Russia and central Asia are increasingly using London property as what the London mayor, Boris Johnson, calls "gold bullion in the sky".

The slump in voters in the five prime areas comes despite a substantial increase in the number of homes: between 2001 and 2011, 4,209 new dwellings were made available, according to census data. Yet the number of voters registered between 2002 and 2014 fell by 2,118.

"Many homes in Westminster are not lived in by families who are part of the local community, but are being used as just investments," said David Boothroyd, a Labour party Westminster councillor, who has analysed the figures. "Super-prime new property in Westminster is sold in Hong Kong and Dubai, not London, and then left empty – to be sold a few years later at a profit."

He said his experience on the council planning committee showed that "almost all the applications are for very large units that are not going to be anything any British family could afford".

A spokesman for the council said: "There has been an increase in residents of varying nationalities across London, some of whom may not wish to vote and therefore do not register."

The data comes as political concern grows about the so-called buy-to-leave phenomenon, which is thought to be driving up prices and locking UK citizens out of the housing market. Across the capital, there are 72,457 empty homes, of which 24,226 are classified as long-term empty, according to latest government figures.

Labour has pledged to block foreign investors from buying new homes in Britain until local people have been offered first refusal.

The Liberal Democrat communities minister, Stephen Williams, has announced a new empty-homes premium, which allows councils to remove the special tax subsidies being given to empty homes. And the free-market thinktank Civitas has proposed a ban on non-EU citizens buying existing homes.

Paul Palmer, director of Empty Homes UK, who used to work for Westminster council, has estimated that there are at least 740 empty properties in London worth £5m or more, the combined value of which would be enough to fund building more than 10,000 affordable homes.

"If you go there after dark, it is soulless," he said of the Westminster enclaves. "You have empty shells kept open by security guards and a couple of security lights. If these properties at the top of the market were made available at the right price, and people were able to move up into them, then the person on the next rung down would be able to step up and that would have a ripple effect all the way down the housing ladder