 It was approved 39-35 by the Basque Parliament, but the Spanish Congress of Deputies rejected it 29-313 in 2005, thus halting the progress of the reform.In September 2007 Ibarretxe declared that a referendum on independence would be held on 25 October 2008, but it was declared illegal and forbidden by the Constitutional Court.Industrial development since the late 19th century led to large-scale immigration of workers from other parts of Spain.