Ask Andreu Mas-Colell, the man in charge of Catalonia's economy, for his thoughts on Scotland's forthcoming independence vote, and he hardly draws breath before answering.

"Admiration, respect and envy," he said. "It's an exemplary process." [...]

Unlike in Britain, Spain already has high levels of regional independence: Barcelona controls its own police, education system and health provisions. The Catalan language is also legally recognised.

But the wealthy region has long felt that it was paying too high a share of Spain's economic burden, and when Mr Mas failed to clinch a better financial pact for Catalonia in 2012, he revived calls for a full referendum on independence.

The spectre of a breakaway Catalonia, which accounts for a fifth of the Spanish economy and 16 per cent of its population, has become a big headache for Mr Rajoy, who is battling high unemployment and the scars of a deep recession. Mr Rajoy has so far vehemently rejected all calls to follow the Scottish path, saying that it simply wasn't possible to grant permission for a vote, which he said was prohibited by the constitution.

For Mr Mas-Colell, however, the Scottish vote gives hope to Catalonia.

"Sooner or later, Spain will have to yield to democratic imperatives," he said, speaking to The Telegraph ahead of Tuesday's vote. "No two countries are the same, but I like to think that the European traditions of democracy imposes norms for behaviour. And the Scottish process is scrupulously democratic."