MADRID: Pro-independence parties in Catalonia won Sunday's regional vote, strengthening a drive for a referendum on secession in defiance of the Spanish Prime Minister, Mariano Rajoy.

The Catalan President, Artur Mas, who called early elections to force the debate on independence, won 50 of the 135 seats in the regional assembly for his Convergencia i Unio party, down from 62, according to the regional government, with 93 per cent of the vote counted. The separatist Catalan Republican Left more than doubled its seats to 21 from 10. Two smaller parties that also back a plebiscite secured 16 seats.

Mr Rajoy, weakened by recession and speculation that Spain needs a European bailout, says a referendum on secession is unconstitutional. Mr Mas's failure to secure a majority for his party may leave him dependent on separatist parties to govern Spain's largest regional economy.

The Republican Left, known as the ERC, ''are the winners,'' said Ismael Crespo, a political scientist at the independent Fundacion Ortega-Maranon research institute in Madrid. ''This is going to complicate things for Mas - he had set out a timetable of four years, but ERC want it in six months. He can't govern without them.''