On the evening of 21 March, Roger Torrent, the speaker of the Catalan Parliament, called an unexpected plenary session to discuss the candidacy of Turull, a senior MP in the Junts per Catalunya, the party of exiled former Catalan president Carles Puigdemont.
The deputy leader of the leftwing separatist ERC party, whose chief is now in jail, is now in Switzerland, according to Spanish media.
Spanish Supreme Court Judge Pablo Llanera on Friday ordered sending five Catalan separatist leaders to prison without the chance of bail to await trial after charging them with "rebellion", a crime carrying a possible sentence of up to 30 years in jail.
Turull will be sent to the prison of Estremera, where two other Catalan leaders, Oriol Junqueras and Joaquim Forn, are already being held.
Thousands of people took to the streets of Barcelona to mark their sign of protest after Spain's High Court jailed five Catalan State politicians who were involved in playing a major role in the region's declaration of Independence.
Crowds of protesters in Spain's Catalonia region have clashed with police after the Supreme Court stepped up legal action against separatists.
Catalonia has been in political limbo since Spanish Prime Minister Mariano Rajoy took over its regional government after it unilaterally declared independence following the October plebiscite.
Marta Rovira, who announced she was taking "the road to exile". Arrimadas accused them of worsening the political showdown with Spain.
Catalan TV showed rallies in support of the jailed leaders elsewhere in the region including in the cities of Vic and Tarragona.
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. Most prominent among them is Carles Puigdemont, Catalonia's ex-president, who has been living in Belgium since October.
Llarena described the case as "an attack on the constitutional State. of unusual gravity and persistence". Thirteen of the defendants have been charged with rebellion by Judge Llarena.
A Supreme Court judge overseeing the rebellion investigation plans to issue indictments Friday.
Rovira, who did not specify where she was headed, is the seventh separatist to flee overseas to escape charges.Separatist parties won regional elections in December called by Madrid after they attempted to secede, retaining their absolute majority in parliament.
The judge also says that the strategy to seek unilateral secession may remain "latent", as the roadmap designed by separatists included plans to renew the leadership of Catalan parties and civil society groups.
The regional parliament now has two months to elect a president and form a government before a new election is triggered. They will be replaced by party members. "Whoever aspires to the presidency of the Catalan government should be free of judicial proceedings", he told lawmakers in the Spanish upper chamber on Thursday morning.
Turull, the only candidate, is not even guaranteed a win in a second round scheduled for Saturday, where he would require a simple majority from the 135-seat Catalan parliament to be elected.