Spain's conservative opposition Popular Party holds a substantial 14-point lead over the ruling Socialists four months before general elections, an opinion poll published Sunday said.

The lead would see the PP romp back into power after eight years, probably with an absolute majority although the number of seats is difficult to predict, Spain's leading daily El Pais said.

The Metroscopia poll released by the paper was carried out just days before Prime Minister Jose Luis Rodriguez Zapatero Friday announced general elections for November 20, four months early, maintaining the time was right as the government had put the country's battered economy on the road to recovery.

Zapatero, who first came to power in 2004 and was re-elected four years later, announced in April that he will not seek a third term as Socialist leader.

The Socialists chose Alfredo Perez Rubalcaba, 60, then interior minister and a party heavyweight, to replace him as party leader, and he will face PP leader Mariano Rajoy, 56, in the November elections.

The Metroscopia poll said 44.8 per cent of voters would back the PP to 30.8 per cent for the Socialists if an election was held now. That compares to figures of 44.7 per cent and 30.4 per cent a month earlier, the organisation said.

But an opinion poll by another organisation, the government-funded CIS, last week indicated that the Socialists have cut the opposition's lead to 7.1 points from 10.4 points since Rubalcaba was named.

The Metroscopia survey also indicated that 77 per cent of Socialist voters believe a PP victory is inevitable.

In municipal and regional elections in May, a huge swathe of the electorate, furious over Spain's economic crisis and soaring unemployment, abandoned the Socialists for the PP.

The collapse of the property bubble in 2008 and the global financial meltdown plunged the country into recession in late 2008 and sent unemployment soaring. The economy stabilised in 2010 and has shown slow growth in early 2011.

The government last year began enacting measures to strengthen bank balance sheets, cut state spending, raise the retirement age, liberalise the labour market and sell off assets in a bid to calm nervous markets.

The Metroscopia poll was conducted July 27 and 28 among 1,203 people interviewed by telephone, with a margin of error of 2.9 per cent.