Time is running out to form a new administration, as a new leader must be found before May 22 or fresh elections must be called. A new election is likely to return similar results to the last, a poll showed on Friday.

All four previous candidates proposed by the pro-independence movement were blocked by the courts because they were either living abroad or being held in custody for their role in a referendum and subsequent declaration of independence.

One of the blocked candidates was Puigdemont himself, who is in Berlin waiting for a German court to rule on whether to extradite him to Spain on a charge of misuse of public funds.

Torra, a pro-independence activist with little previous political experience who has published books on the history of Catalonia, must win an absolute majority in Saturday's vote to be elected leader.

If he does not get this backing, a simple majority in a second vote 48 hours later, on Monday, will be sufficient under Spanish electoral law.