MADRID (Reuters) - Support for Spain's ruling Socialists has slipped ahead of elections in November, with neither the left nor the right-wing blocs on course to win a majority, a Sigma Dos poll in El Mundo daily showed on Thursday.
The poll was the first to be published since Spain's Supreme Court handed down prison terms to nine Catalan leaders who had sought to declare an independent state, triggering unrest in the northeastern region of Catalonia.
Socialist leader Pedro Sanchez last month called an election for Nov. 10 after refusing to strike a coalition deal with the far-left Unidas Podemos, hoping that the repeat ballot, coming just seven months after the last vote, would bolster his party.
The Sigma Dos poll predicted that while the Socialists would once again emerge as the largest party, they would win just 122 seats in the 350-seat parliament against the 123 they took in April. Unidas Podemos was on course to take 33 seats against 42 last time around, the polls showed.
The Conservative People's Party (PP) was forecast to see its number of lawmakers jump to 98 seats from 66.
The far-right Vox party was seen becoming the third largest political force, climbing to 34 seats from 24, overtaking the centre-right Ciudadanos group, whose seats would plunge to 19 from 57, the poll said.
Pollsters predicted similar success for Vox ahead of April's election, but in the end it fell short of the mark.
PP, Vox and Ciudadanos have adopted an uncompromising approach to the Catalan crisis and have called on the Socialist government to take control of the autonomous region.
Sanchez has said he will act firmly and proportionately, and in concert with other political parties, to manage the situation.
(Reporting by Ingrid Melander, Ashifa Kassam, Editing by Crispian Balmer)