WA Liberals won't block payroll tax hike

The WA Liberal opposition will not block the Labor state government's proposed payroll tax hike as a state budget repair measure.

The WA opposition will not vote against the Labor government's proposed payroll tax increase, despite describing it as a broken election promise.

The tax hike will be applicable only to big companies with a payroll of more than $100 million a year - less than one per cent of businesses - and is expected to raise $435 million over the next four years.

Opposition leader Mike Nahan on Tuesday said the payroll tax increase was different to the gold royalty hike that the party recently knocked back.