Portugal's two main opposition parties on Wednesday ruled out entering a coalition government with the ruling Socialists, but vowed to be a "responsible opposition" that safeguards political stability.

Socialist Prime Minister Jose Socrates won a parliamentary election on Sept. 27, but his party lost its absolute majority in parliament, meaning it needs alliances, be they permanent or temporary, to pass bills.

The leaders of the center-right Social Democratic Party (PSD) -- the second-largest in parliament -- and of the third-placed right-wing CDS-PP met Socrates on Wednesday, part of consultations on forming a new administration.

"The PSD is not available for coalitions or parliamentary pacts," said PSD leader Manuela Ferreira Leite.

"But we are totally available to be a responsible opposition, which means that we won't be against the proposals that are good for the country just because they come from the government," she added.

Socrates' centre-left Socialists won 97 seats, down from 121 four years ago, in the 230-seat parliament. The PSD secured 81 seats, the CDS-PP got 21 seats, the Left Bloc won 16 and the Communist-Greens coalition got 15.

Socrates will meet leaders of the other parties on Thursday.

"We want to be the best opposition to the government...I've never been obsessed with (cabinet) posts and I can say it again now," CDS-PP chief Paulo Portas told a news conference.

"I've always defended a culture of compromise and negotiations ... It's also part of our sense of resposnibility not to be opposition just for the sake of being opposition ... That's the attitude we will maintain," Portas said.

Referring to the government's first test in parliament -- the approval of its programme, which should be submitted to the house before the end of the month -- Portas said his position was that "it is not time for irresponsible attitudes".

Western Europe's poorest country needs to swiftly address problems such as rising debt and unemployment, a growing budget deficit and a widening wealth gap with European partners. The 2010 budget bill must be presented to parliament before year-end.

Reuters