Portuguese civil servants and soldiers staged an anti-austerity protest in Lisbon on Saturday, a sign of the rising social tensions in debt-hit Portugal over deep cuts in spending.

The country's two main public workers unions, the CGTP and UGT, organised the march through the streets of the Portuguese capital to try "to prevent the offensive launched by the administration against workers," said a union organiser Ana Avoila.

Workers shouted and carried banners reading, "No to stealing wages", "Yes to work, no to joblessness".

Neither the police nor organisers have yet given a crowd estimate, though thousands had been expected to join the protest.

Saturday's protest also included a march by soldiers, in civilian clothes, who are opposed to the austerity measures and in particular a freeze on promotions.

"Blindly applying austerity measures is harmful for the military. The army cannot be treated like that," Antonio Lima Coelho, 52, the head of an officers' association, told AFP.

The dual demonstrations came the day after Portuguese lawmakers gave preliminary approval to the government's 2012 austerity budget aimed at putting the country's finances in order.

Prime Minister Pedro Passos Coelho's centre-right government, elected in June, has a comfortable majority in parliament with 132 of the 230 seats, and the budget's final vote is set for November 30.

Portugal was bailed out in May to the tune of 78 billion euros ($107 billion) by the European Union and International Monetary Fund and the government has pledged to raise taxes and cut spending, an unpopular mix which has hit growth hard.

The 2012 budget, described by Passos Coelho earlier in the week as "very tough," will scrap annual bonus payments worth two months salary for civil servants and for pensioners with income above 1,000 euros per month.

The working day will be increased by 30 minutes in the private sector, while health and education spending will be slashed, topping off a series of measures already adopted in efforts to reduce the deficit.

Passos Coelho concedes that the measures are even tougher than those required under the EU-IMF bailout terms but says they are necessary to ensure its targets are met in the face of difficult economic conditions.

The government estimates that the budget will see the economy shrink 2.8 percent in 2012 while the EU puts the downturn at 3.0 percent, for the worst performance in the bloc.

Portugal followed Greece and Ireland in needing a bailout and EU, IMF and European Central Bank officials are currently in Lisbon to review progress under the bailout deal and decide whether to clear the next eight-billion-euro loan installment.

Under the accord, Portugal needs to reduce its public deficit from 9.8 percent of gross domestic product in 2010 to 5.9 percent by the end of 2011, but it stood at 8.3 percent earlier this year, putting that objective in doubt.