Prime Minister Pedro Sanchez will chair his weekly cabinet meeting in the Catalan capital of Barcelona Friday, as a part the effort to resolve the political conflict.
That declaration prompted Madrid to take control of the region — which has 7.5 million people and accounts for about a fifth of Spain's economy — and to arrest pro-freedom leaders.
Hundreds of national police have been deployed in Barcelona to guard the cabinet meeting due to fears of protest.
"(Sanchez's government)... will want to provoke us, they will be angry, they would like us to be violent, and they will not succeed," the nine prisoners said in a letter released by their political parties.
"Our strength also lies in maintaining, always and everywhere, a civic and peaceful attitude."
The signatories are all in jail awaiting trial on charges of rebellion and misappropriation of funds.
Four of them — Jordi Turull, Josep Rull, Jordi Sanchez, and Joaquim Forn — unexpectedly called off a hunger strike Thursday that they began at the start of December in protest of the legal process.
"Today, after 20 days since it began, we are ending our hunger strike," the spokeswoman Pilar Calvo said reading a statement from the protesters.
That announcement is likely to ease tensions before an expected meeting later Thursday between Sanchez and pro-independence regional leader Quim Torra.
Though no format for the encounter had been agreed to by Thursday morning, Madrid has said it would be brief and informal. The Catalan administration views it as an official meeting to discuss political discrepancies and the prisoners.
Friday's planned demonstrations against Madrid will be the latest of many, some of which have drawn hundreds of thousands.
During last year's independence vote, Spanish police attempted to shut down impromptu voting stations, provoking international outcry with the use of batons and rubber bullets in melees that injured dozens.
Catalonia was granted full autonomy in 1979 when the autonomous community of Catalonia was established. In 2006 Catalonia was declared a “nation” and had the same level of taxation responsibility as the Spanish government.
However, in 2010, the Spanish Constitutional Court struck down the autonomous status ruling that Catalans are a “nationality” but Catalonia is not a “nation”. In 2013 the Catalonia regional parliament passed a measure which called for a referendum on independence from Spain to be held in 2014.
Artur Mas, the leader of the Convergence and Union, a Catalan nationalist electoral alliance which was dissolved in 2015, said that the referendum would be held on Nov. 9, 2014. The then Spanish Minister Mariano Rajoy opposed the measure and the Constitutional Court started a discourse of the legality of the vote.
Finally, an informal poll of Catalan opinion was held which showed that over 80 percent Catalans voted in favor of independence.
In March 2017 a Spanish court found Mas guilty of contempt for calling the 2014 referendum, and he was barred from holding public office for two years.
However, Catalan leaders announced in June 2017 that Catalonia would hold a binding referendum on independence on Oct. 1, 2017. The October 2017 vote was marred with violence and since then Catalans have been holding protests regularly while their leaders are imprisoned by the Spanish government.