Ex-Catalonia chief Carles Puigdemont, currently in self-exile in Belgium, announced on Sunday that he is running in the upcoming European elections.
Puigdemont, 56, is to be the leading candidate of the Junts per Catalunya party.
"It is the moment to make another step to internationalise the self-determination right of Catalonia from Europe's heart to all the world," Puigdemont wrote on Twitter.
Puigdemont fled Spain in October 2017 after the country's government imposed direct rule on Catalonia following a referendum on independence ruled illegal by Spanish courts.
He faces charges of rebellion and sedition which if convicted could see him sentenced to up to 25 years in prison.
Despite not being in the country, Puigdemont was re-elected to the Catalonia parliament on December 21, 2017. Pro-independence parties, which retained a slim majority, attempted to elect him as president but were blocked by Spanish courts.
Spain's Supreme Court dropped the European Arrest Warrant against him in July last year after Germany refused to extradite him on rebellion charges, which it does not recognise. A German court ruled however that Puigdemont could be charged for misuse of public funds.
Puigdemont current resides in Waterloo, in Belgium.
Other prominent figures of the Catalan independence movement — Jordi Sànchez, Quim Forn, Jordi Turull and Josep Rull — who are currently in jail for their role in the independence referendum are also running in the May 26 EU elections.
In a letter posted on the Junst per Catalunya's website, they wrote: "We're going out to win, as we did on December 21, 2017."
"We will make our commitment to honest politics — with a return to dialogue, and harmony between peoples and defence of democracy — central to our action.
"An action that will exercise the right to self-determination of Catalonia," they added.
_The article was updated as an earlier version erroneously stated that Carles Puigdemont was in self-exile in Berlin. _