Catalonia's president, Artur Mas, who had planned an official referendum vote on November 9 on the region's breakaway, was forced to downgrade the event after the Spanish government launched a legal challenge at the Constitutional Court.
Spanish Prime Minister Mariano Rajoy's conservative governmen asked the Council of State, an advisory body, for its opinion on this new consultation, a first step towards challenging the new vote in the Constitutional Court, the government said in a statement.
The Council of State was asked to issue its ruling quickly so a decision on how to respond to the Catalan vote can be made during the next weekly cabinet meeting, which is expected on Friday, the statement added.
If the court agrees to study a new challenge by the government, the vote will be tentatively suspended.
Proud of their distinct language and culture, Catalonia's 7.5 million inhabitants have increasingly been demanding greater autonomy over recent years. The region accounts for nearly a fifth of Spain's economic output.
Polls indicate that most Catalans want a referendum, but are roughly equally divided over independence. The issue has embittered the region's relations with the government.
The Catalan government has said 5.4 million Catalans aged 16 and over will be eligible to vote, along with certain foreign residents in the region and Catalans living abroad. The vote will be largely organised by volunteers.
About 1,255 voting stations will be set up across nearly all of Catalonia's more than 900 municipalities and in 17 foreign cities, it said. Provisional results will be available from November 10.