TORONTO - The Opposition says the Liberal government's public sector wage freeze is so unfair it has led to the biggest union drives in Ontario since the Great Depression.

The Liberals asked public sector workers to take a two-year wage freeze in 2009 but imposed one on managers and non-unionized staff, so some workers got raises while others didn't.

Progressive Conservative Leader Tim Hudak says the wage freeze divided workers and prompted many to join a union, especially in the province's hospitals.

Hudak says the Ontario Public Sector Employees Union increased its membership by 3,000 hospital workers because of the unfair Liberal wage freeze.

The union's website says "a large factor" in the hospital employees' move to join was the wage freeze for non-unionized public-sector workers.

Hudak says the cash-strapped province must legislate a pay freeze for doctors, teachers and about a million public sector workers to save $2 billion over two years.