Artur Mas yesterday told La Vanguardia, Catalonia's leading newspaper: "If I call a consultation, not to declare the independence of Catalonia nor to break with the Spanish state, but to know the opinion of the citizens of this country, a knee-jerk anti-democratic response from Spain would be pretty bad and disgraceful in the view of the entire world."
Prime Minister Mariano Rajoy has pledged to go to court to block any Catalan attempts to hold a referendum, arguing sovereignty is a matter for all of Spain to decide, but Mr Mas said there was another possible approach.
He added: "It is what I call the solution tolerated by the central government. They let us hold the consultation, they don't get involved, and afterwards we go to Madrid to negotiate."
Over the past three years the independence movement in Catalonia has gained force, with roughly half of Catalans saying they want independence from Spain and a much bigger majority saying they should have the right to decide.
But Mr Rajoy, who is struggling to pull Spain out of six years of economic stagnation, said: "The unity of all Spaniards is what makes us great, and what the great majority of Spaniards want. Those who don't agree with that must respect that desire, and respect the law."