Fugitive Catalan separatist leader Carles Puigdemont has said he is ending his bid to be reappointed president of Spain's north-eastern region.

He said he was stepping aside in favour of detained activist Jordi Sanchez.

Mr Puigdemont is in self-imposed exile in Belgium and has been told by Spain he faces arrest if he returns to Barcelona to be sworn in.

This followed Catalonia's independence referendum last October, which the Spanish courts declared illegal.

What did Mr Puigdemont say?

"I will not put myself forward as candidate to be appointed regional president," Mr Puigdemont said (in Catalan) in a video posted on social media.

The 55-year-old said he was doing this in an attempt to unblock a political impasse following Catalonia's independence bid.

Mr Puigdemont also posted a link to another video address (in English), in which he said: "We will achieve independence for the people we represent - that is our mandate and we will fulfil it."

He said his lawyers had appealed to the UN human rights committee, accusing the Spanish authorities of violating Catalonia's right to self-determination.

The Spanish government welcomed Mr Puigdemont's move to abandon his presidency bid, AFP news agency reports, with a source saying Catalonia needed "to have a regional president as soon as possible".

Who is Jordi Sanchez?

He is a former leader of the Catalan National Assembly, a grassroots movement advocating independence.

Mr Sanchez, 53, and several other Catalan pro-independence politicians have been imprisoned in connection with the independence referendum, which was met with a heavy police crackdown and attracted global attention.

On the Twitter account run in his name while he is in prison, Mr Sanchez wrote on Thursday: "It is a great honour and enormous responsibility to be able to represent the people of Catalonia."

Mr Sanchez's nomination would face strong opposition from Madrid, the BBC's Europe reporter Gavin Lee says.

This is Spain's biggest political crisis since democracy was restored in the country in 1975.

Following the referendum, the central government in Madrid sacked the Catalan regional government, imposed direct rule and called new elections but pro-independence parties returned with a slim majority.

In a setback for the pro-independence cause, a survey published by the respected Catalan Centre for Opinion Studies last week suggested support for independence had dropped sharply, with a majority of Catalans now against the idea.

According to the poll, 53.9% reject independence while 40.8% support it - down from 48.7% in October.