Vancouver Mayor Gregor Robertson is renewing calls for a tax on vacant homes as an incentive to increase housing availability in the city's tight rental market.

"It's an approach to get people to rent empty homes," said Robertson on Tuesday.

"If we can create that momentum, than it creates more rental housing. Obviously that's income to people who have empty homes."

Less than one per cent of homes in Vancouver are available for rent, according to the Canadian Mortgage and Housing Corporation.

A recent report on empty homes in Vancouver indicated 4.8 per cent of the city's homes were empty — which Robertson says represents more than 10,000 houses and condos sitting empty for more than a year.

Robertson acknowledged it would be a challenge to get the province on board with the tax.

"The city's powers are very limited with housing and that's why we're in this predicament. That's why we need support from the provincial government," Robertson said.

However, the province points out the city's own report shows the rate of empty homes has remained stable over the last 14 years and is in line with other major cities across Canada.

It also said the report found there is no correlation with the number of empty homes and the cost of real estate, and that a tax wouldn't help affordability.

Instead, the province says it's focusing its efforts elsewhere to increase housing affordability.

"Finding ways to bring new supply of housing — rental and market — into development for people to access is a priority," said the Finance Ministry in a written statement.

"In a city as desirable and land-constrained as Vancouver, an essential way to promote appropriate housing options for income earners at all levels is to encourage densification."

The ministry also said it is working closely with municipalities to find solutions to the region's housing affordability issues.

With files from Richard Zussman