LISBON (AFP) - Piles of garbage mounted in the streets of Lisbon on Sunday as refuse collectors pursued a nearly week-long strike over budget cuts.

The strike, which started on Dec 23, was prompted by the city's use of outside contractors and the privatisation of essential services, according to a statement from the CGTP union confederation.

The CGTP said it would continue the strike until Jan 5, though Lisbon Mayor Antonio Costa said he thought it would take a few more days before things return to normal.

The authorities have asked residents not to put out their rubbish during the strike.

This latest strike is one of several to hit Portugal's public services in recent months as unions oppose an austere 2014 budget.

Next year's budget aims to save 3.9 billion euros (S$6.8 billion), partly through cutting public sector salaries and pensions.

Transport strikes are expected in the coming weeks.