The leader and nine of his officials were told to repay the costs of the 2014 vote, which was a symbolic ballot by pro-independence campaigners and subsequently ruled illegal by the country’s constitutional courts.

Spain’s accounting watchdog ruled that the Catalan authorities had misappropriated the public money. It said Mas had overall responsibility to repay the total amount, with interest, but the other officials must also contribute.

Mas and his colleagues used public money to buy thousands of computers used in polling stations and to pay for a website and advertising.

Mas staged the 2014 independence ballot, despite failing to get Spanish authorities to allow a full referendum.

Mas was barred from public office for two years in March 2017 for holding the informal referendum but has continued to speak for the region’s separation.

Catalan separatists held another illegal vote on 1 October last year, which police sought to shut down.