The average cost of renting a one-bedroom house in parts of London has soared by more than 50% in the past five years, a new study has revealed.
Research by the GMB union showed the average rent in Hounslow has increased from £825 a month to £1,248 since 2011, the biggest increase in the capital.
Average rents for one-bed properties have shot up by at least 30% in 11 London boroughs, taking the average for the capital to £1,250 a month, according to the report.
The figure dwarfs the average for England as a whole, of £550.
The GMB said average rents for two-bedroom houses in London increased by 25% to £1,500 a month between 2011 and this year.
Warren Kenny, senior officer of the GMB, said at the union's annual conference in Bournemouth: "These figures show that the housing crisis in London is getting worse as rents soar under a Tory government.
"Rents in one borough for basic accommodation soared by over 50% at a time when wages are frozen or being cut.
"These soaring rents coincide with the explosion in the size of the private rented sector and the growth in the billions of taxpayers' money paid in housing benefits to private landlords."
A Communities and Local Government Department spokesman said: "This Government is committed to creating a bigger, better private rented sector, which meets the needs of tenants and landlords, while encouraging record investment.
"That's why we've set out the boldest vision for housing in a generation, including recently announcing two multimillion-pound deals that will see more than 1,000 rental homes built in London.
"We're doing all of this without the need for excessive state regulation that would destroy investment in new housing, push up prices and make it far harder for people to find a flat or house to rent."