

"The head of the government is obliged to enforce the law and this (referendum) is illegal," he said at his first news conference since holding talks on Wednesday with the president of the regional government of Catalonia, Artur Mas.

During the meeting, the first between the two leaders since August 2013, Mas told Rajoy that he was "absolutely determined" to hold the referendum.

"I don't know what will happen on November 9.

Mr Mas has said that he will not do anything illegal," Rajoy added during the press conference.

Rajoy insists a referendum would be illegal under Spain's constitution as it states sovereignty must be held nationally and not regionally.

But Mas points to polls that show a large majority of Catalans back his planned vote.

Mas, who has headed the Catalan government since 2010, began pushing for a referendum after he failed to clinch a better financial deal from the central government in 2012.

After regional polls that year, his conservative Convergence and Union party allied with the separatist Esquerra Republicana party, which has pressurised Mas into committing to a referendum.

With an economy roughly the size of Portugal's, Catalonia, a region of 7.5 million -- 16 percent of the Spanish population -- has long been an economic powerhouse in a country where just under a quarter of people are unemployed.

Proud of their distinct language and culture, a growing number of Catalans resent the redistribution of their taxes to other parts of Spain and believe the region would be better off on its own.

Support for independence itself was about 45 percent in April, according to the regional government's most recent poll, compared with about 20 percent before Mas took office.

AM/