Hundreds of thousands of Catalans in northeastern Spain are due to increase pressure on Madrid for an independent , breakaway state Wednesday by forming a human chain for 400 kilometers ( about 250 miles ) . The human chain is organized by the grass-roots , citizen-led Catalan National Assembly , which last year on September 11 -- Catalonia 's national day -- turned out an estimated 1.5 million people in Barcelona , the regional capital . Catalan politicians followed up by demanding a referendum on self-determination by the end of 2014 , which the Spanish government in Madrid staunchly opposes . Spain 's next threat : Losing 20 % of its economy . While the political battle continues between Spain 's two largest cities , Madrid and Barcelona , the human chain has emerged as the latest rallying point . Organizers say 370,000 Catalans have signed up to take part , and they predict tens of thousands more will also participate . The chain will traverse Catalonia from the north , near the French border , to the south , on its border with the Spanish region of Valencia . `` It will be an innocent but powerful image to push the process ahead , holding hands , '' said Alfred Bosch , who represents Catalonia 's pro-independence Republican Left party in Spanish Parliament in Madrid . Dubbed the `` Catalan Way Toward Independence , '' the human chain shows the process can only `` go ahead , forward , and not back , '' Bosch said . But the Spanish government doubts that . It says that Catalonia , with 7.5 million people , already has broad home-rule powers , including its own parliament , police force and control over education and health . Catalonia 's fight for independence : Lessons from the Dutch . And Madrid insists that the Spanish Constitution does not allow any of Spain 's 17 regions to unilaterally break away , even one like Catalonia that has its own flag and language . On the eve of the human chain , Spanish Foreign Minister Jose Manuel Garcia-Margallo said political leaders should find a way to keep Catalonia within Spain . But Catalan 's president , Artur Mas , in an opinion article published Wednesday in The New York Times , wrote : `` We ... seek no harm to Spain . We are bound together by geography , history and our people , as more than 40 percent of Catalonia 's population came from other parts of Spain or has close family ties . We want to be Spain 's brother , as equal partners . '' Catalan parliament pushes self-determination . Catalonia says it 's been the junior partner for too long . It produces 19 % of Spain 's wealth and says it sends far more in taxes to Madrid than it gets back in central government spending . It recalls a long history of slights , and at certain times outright repression , by Spain . The human chain will start at 17:14 local time ( 11:14 a.m . ET ) , to honor Catalans who on September 11 , 1714 , lost a decisive battle to Spanish troops . The chain will last about an hour . The current polemic is not just between Catalonia and Spain . Within Catalonia , there is also tension between leading political forces over the timing , and the potential wording , of the referendum . President Mas , whose center-right Convergence and Union party governs only because of support from the Republican Left , seemed to leave the door open last week for a vote on self-determination later than 2014 , perhaps in 2016 . He has since repeated that he favors the 2014 deadline . But the Republican Left and those organizing the human chain insist it must be by the end of 2014 , with or without the consent of Madrid . Various opinion polls show a very large majority of Catalans want the right of self-determination . But if independence makes it to the ballot , polls show the result could be tighter , some predicting a victory in the 50 % range .
Organizers say 370,000 people have signed up to take part . The chain is expected to stretch for 400 kilometers ( about 250 miles ) Catalan politicians are calling for a vote on self-determination by the end of 2014 . But the Spanish government says that Catalonia already has sufficient home-rule powers .