MADRID (REUTERS) - Spanish authorities are monitoring borders to make sure that fugitive Catalan separatist leader Carles Puigdemont does not sneak back into Spain to take up the presidency of the regional Parliament again, a senior minister said on Tuesday (Jan 23).

Mr Puigdemont has said he can rule from self-imposed exile in Belgium, where he fled to in October to avoid arrest for his part in organising an illegal referendum on a Catalonian split from Spain and a subsequent unilateral declaration of independence.

The Madrid government, however, says no one can be named or rule remotely.

Spanish Interior Minister Juan Ignacio Zoido said he was worried that the 55-year-old, who faces arrest the minute he steps back in Spain, could now try to discreetly return to the Parliament in Barcelona for a vote on his candidacy.

"We're making sure this cannot happen, at the borders and within the borders, everywhere," Mr Zoido told Antena 3 TV.

Spanish authorities were working day and night to prevent any attempt by him to return undetected, he said.

"We'll make sure he cannot get in, even (hidden) in the boot of a car," he said.

Catalan lawmakers are set to vote on Mr Puigdemont's candidacy by Jan 31.

Mr Puigdemont on Tuesday withdrew a request to be allowed to vote for himself by proxy, a source in his party said, without saying why he had dropped that demand or if it meant he planned to be in Parliament in person for the leadership vote.

He was visiting Denmark on Tuesday, his first trip outside Belgium since he arrived there in October following his dismissal by the Madrid government and its imposition of direct rule on the semi-autonomous region.

Spanish Prime Minister Mariano Rajoy called a new regional election in December in a bid to defuse the crisis but his gamble failed when separatist parties won a majority, giving new impetus to the independence movement.

Mr Puigdemont, a former journalist, potentially faces decades in prison in Spain if he is convicted of the charges levelled against him, including rebellion and sedition.

Mr Rajoy has said the Madrid government would appeal to the courts and maintain direct rule of Catalonia if Mr Puigdemont was elected while abroad.