MADRID (Reuters) - Organizers of sailing’s Barcelona World Race said on Thursday they were suspending the 2018-19 event due to political unrest in the Spanish region of Catalonia which had hit sponsorship.

An illegal referendum and declaration of independence by Catalan politicians in October prompted Spanish courts to jail or seek the arrest of participants and regular mass protests across the industrialized region.

“Political instability has made it difficult to guarantee delivering the event to the standards a round-the-world race deserves,” the Barcelona Ocean Sailing Foundation said.

The 10-year-old regatta, which is held every four years, is a two-crew round the world yacht race of some 26,000 nautical miles (48,152 kilometers) starting and finishing in the Catalan capital of Barcelona, with a stop-over in Sydney.

The clash between the northeast region, which produces around a fifth of Spain’s economic output, and the government in Madrid has led thousands of companies based in Catalonia to relocate their legal headquarters to other parts of Spain.

“A sporting event of this scale requires significant private sponsorship, which is its only source of funding,” they said, adding that they had found the political climate had prevented them from ensuring a reliable sponsorship process.

Sponsors of the last Barcelona World Race in 2014-15, which was won by Bernard Stamm of Switzerland and Jean Le Cam of France, included Estrella Damn, Renault and Johnson & Johnson.

The board of trustees for the Barcelona World Race includes the Barcelona City Council, the Barcelona Chamber of Commerce, Port of Barcelona and the Barcelona Trade Fair.

The organizers said they were beginning talks with the IMOCA class association “with the aim to secure a future edition of the Barcelona World Race in 2022-2023”.