"External aid will be inevitable, so it would be better to face it without a lot of delays," said the head of the northeastern region, who is pushing for greater financial independence from the rest of Spain.

The bailout prediction flies in the face of Spanish Prime Minister Mariano Rajoy's studious refusal to say whether the country needs rescuing, insisting instead on the need to study the matter.

Mas said there was no reason that he should share the opinion of the Spanish government.

"Since the Spanish government has more information, it should decide when it is done and whether it is done or not," Mas said.

"I understand from the information we have that Spain will end up having to have a rescue," he added. "Spain has the potential to emerge from this situation but it needs help for a period."

Mas said there was no need to dramatize the situation, saying the European Union had previously provided Spain with lots of help with its economic development.

"Spain is already used to being helped," he said.

"It's another matter entirely to know that there are certain countries that have a public opinion that they don't want it (the bailout) to be requested," Mas said.

Prime Minister Jyrki Katainen of Finland, which is among the eurozone fiscal hardliners, said in a Wednesday newspaper interview that he felt it unlikely Spain would request a full sovereign bailout.

A German government source, speaking on condition of anonymity, said this week that Berlin did not believe Spain could make a "convincing case" for a rescue while it can still borrow on the financial markets.

Spain's right-leaning Popular Party government has refused to say if a bailout is coming.

Asked on Tuesday whether a sovereign rescue was imminent, the prime minister simply replied: "No."