What now for Catalonia's deposed separatist leader in Belgium?

Catalonias deposed separatist leader Carles Puigdemont, facing possible prosecution for rebellion in Spain, appeared in Brussels on Tuesday saying he planned to stay in Belgium but denying rumours he would try to seek asylum.

His presence creates a headache for the Belgian government, which was quick to say he had come without their knowledge or invitation under Europe's free movement rules.

How long can he legally stay in Belgium?

As an EU citizen Puigdemont can stay in Belgium for 90 days without informing the authorities, Dominique Ernould of the government's Foreigners' Office told AFP.

To stay longer, he must submit a residency application. This can be granted on the basis of employment, for family reunion or by showing he has the financial means to support himself.

But if he were to leave Belgium before the 90 days was up -- by crossing the border to France or the Netherlands, for example -- the clock would be reset "and an EU citizen could once again stay for three months," Ernould said.

If charged in Spain, could he claim asylum?

Spanish prosecutors want to charge Puigdemont with sedition and rebellion, punishable by up to 30 years in jail, leading many to suspect he fled to Belgium to seek sanctuary -- particularly after he consulted a lawyer who has dealt with asylum cases involving Spaniards from the once-restive Basque Country.

EU citizens can claim asylum in Belgium, according to the country's CGRA refugee agency.

But Puigdemont has denied planning to do so and moreover even if he did, the chances of success would seem to be very slight.

"It's quite exceptional to obtain asylum for a citizen of a European Union country," Dirk Van Den Bulck of the CGRA told RTBF television.

Belgium will consider asylum applications from other EU countries, but works on the principle that members of the bloc are safe and respect human rights. In the last five years Belgium has not granted asylum to any EU citizens.

Puigdemont would have to prove a "threat of persecution" in his country of origin and an impossibility of being protected there, Van Den Bulck said.

If Spain issues a European arrest warrant for Puigdemont "there would be very little room for Belgium to refuse it", said Maxime Chome, a Belgian legal expert.

What are the implications for Belgium?

The Spanish standoff is already causing problems for the Belgian government led by Prime Minister Charles Michel, who rules in coalition with Flemish separatists sympathetic to the Catalan cause.

The French-speaking Belgian leader was quick to stress after Puigdemont's news conference that his government had "not undertaken any step to encourage Mr Puigdemont's arrival on Belgian soil" and warned him not to expect special treatment.

But on Saturday Michel's immigration minister Theo Francken, from the Flemish separatist N-VA party, said Belgium could offer asylum to Puigdemont, infuriating Spain.

The EU and its member states have been resolute in their support for Madrid during the Catalan independence crisis, but Michel has been more muted, calling for dialogue to resolve the standoff.