Joan Boix has been attending separatist demonstrations in Catalonia for at least five years and he contributes to the campaign for a split from Spain.

But as the regional government in Barcelona girds its supporters for a final push that it hopes will deliver independence, the 62-year-old executive is hesitating. Hardliners talk of setting up a rogue Catalan tax agency or a general strike in order to force the issue. But Boix has a company to worry about.

"Most of the businessmen I know have to make debt repayments so an indefinite strike is a hard sell,'' he said.

Regional President Carles Puigdemont is trying to increase his leverage as officials in Madrid vow to block his plans for a referendum in October. But the potential costs of a collision with the Spanish state are become clearer for Puigdemont and his supporters.