File Photo: Catalans form a 400km long chain last September to press for independence

The Spanish government Saturday said Catalonia would not be allowed to hold an independence referendum, shortly after the region’s leader set a November 9 date for the vote.

No one is “above the national will of all Spaniards,” Deputy Prime Minister Soraya Saenz de Santamaria told a news conference shortly after Catalonia’s president formally called the vote. “This referendum will not take place because it is unconstitutional.”

The government immediately began the process of appealing to the Constitutional Court, which is expected to annul the decree signed by Mas.

The independence movement in Catalonia has gathered strength in recent years.

Fired up ahead of the referendum in Scotland this month, 1.8 million people protested in Barcelona on September 11 to be allowed to hold their own vote.

“Catalonia wants to express itself, it wants to be heard and it wants to vote,” Mas said after he signed the decree calling a referendum in a ceremony at the Generalitat Palace in Barcelona.

The Spanish government’s response was swift, with Saenz de Santamaria telling a news conference in Madrid: “This referendum will not take place because it is unconstitutional.

“We deeply regret the president’s move and we consider it to be a mistake — it will cause Catalan society to fracture, it will divide the Catalans and distance them from Europe,” she said.

Mas has vowed to let Catalans vote on breaking away but has also promised to respect Spanish law.

Catalonia is Spain’s economic powerhouse, although it too suffered in the property crash and the resulting crisis that gripped the country from 2008 to 2012.

Proud of their Catalan language and culture, many of the region’s 7.5 million inhabitants feel short-changed by the government in Madrid, which redistributes their taxes.

Here are key dates in the campaign for the Catalonia region to gain independence from the rest of Spain:

October 25, 1979: During Spain’s transition to democracy after the death in 1975 of the dictator Francisco Franco, Catalans approve in a referendum a charter defining Catalonia as an autonomous community under Spain’s constitution.

June 18, 2006: Catalans approve a new autonomy charter, negotiated with the then Socialist government and approved by the national parliament, increasing their fiscal and judicial powers and describing Catalonia as a “nation”.

September 2009: The small town of Arenys De Munt becomes the first in Catalonia to hold a symbolic local vote on regional sovereignty. Hundreds more towns follow over subsequent months.

June 2010: Responding to an appeal by the conservative Popular Party, Spain’s Constitutional Court approves parts of the 2006 autonomy charter but rules that the word “nation” to describe the region has “no legal value”.

September 11, 2012: More than a million people swamp Barcelona in a demonstration demanding independence for Catalonia. Similar mass rallies fill the city on the same date in 2013 and 2014.

September 20, 2012: Prime Minister Mariano Rajoy rejects Mas’s request for greater tax-and-spend powers for Catalonia. Five days later, Mas calls a snap regional election promising to hold a referendum on the future of Catalonia.

November 26, 2012: Mas’s centre-right CiU alliance wins the snap election overall but loses its absolute majority in the regional parliament, forcing it to broker an alliance with the left-wing nationalists ERC.

January 23, 2013: Catalonia’s parliament approves a declaration of sovereignty that it says permits the region to vote on self-determination, but Spanish judges rule that unconstitutional in March 2014.

December 12, 2013: Political parties in Catalonia agree to call a referendum on independence for November 9, 2014.

September 27, 2014: Mas signs a decree formally calling a vote on independence for November 9. Spain’s government vows to block it immediately through an appeal to the Constitutional Court.