Madrid - Portuguese voters on Sunday defied European trends and returned the ruling Socialists to power with an enhanced share of the vote, but denied them an absolute majority, according to the first official results.

PS regained power

With all the votes counted, the Partido Socialista (PS) led by Prime Minister Antonio Costa won 36.65 per cent of the vote, up from 32.31 per cent four years ago, state broadcaster RTP reported early Monday. The conservative opposition Social Democratic Party (PSD) lagged at 27.9 per cent.

Portugal is one of the few countries in Europe where Socialists are still going strong and right-wing populists play no significant role in politics.

"The PS has strengthened its position in Portugal," Costa told hundreds of supporters at a hotel in the capital Lisbon, who shouted "victory, victory, victory!"

Costa, a 58-year-old trained lawyer and former mayor of Lisbon, will most likely have to continue to depend on the support of other parties.

While the number of Socialist lawmakers in parliament has risen from currently 86 to at least 106, the PS does not have the 116 seats needed to rule by itself.

Results after all votes counted in electoral districts

During the current legislative period, it was supported by the Marxist Left Bloc (BE) and the Green-Communist alliance CDU without forming a formal coalition.

The BE got 9.67 cent, while the leftist CDU alliance came in at 6.46 per cent.

The conservative PSD, formerly the strongest parliamentary party, will have 77 seats in parliament in future, down from 89 seats.

Costa said Sunday that there had been no talks with other parties about the formation of a future government before the election.

The BE could become a thorn in his side, with party leader Catarina Martins saying there is a lot more to do in the fight against the acute lack of housing in cities and the neglect of other parts of the country.

Economic growth since 2015

Since it took over in the autumn of 2015, Costa's minority government has managed to secure growth and stability in a country previously shaken by the financial crisis.

The European Union and the International Monetary Fund saved Portugal from bankruptcy in 2011 with an aid package of 78 billion euros (86 billion dollars).

After three years under the EU rescue package, the country has been financially back on its feet since 2014; however, the austerity policies of those years cost the conservatives power.

In the years that followed, Costa succeeded in balancing what had hitherto been considered the impossible: he relaxed austerity policies, increased social and other spending, and at the same time complied with the requirements of Brussels.

The economy also grew well above the EU average, thanks to a tourism boom. At 6.7 per cent, the unemployment rate has recently reached its lowest level since 2002.