AFP, Barcelona

Catalan leaders came under intense domestic and international pressure yesterday to halt plans to break away from Spain after the region's president repeated his threat to declare independence and the government warned it would act to block it.

The sides dug in as the clock ticked down to an evening session today in the regional parliament where separatists have called for an independence declaration, a plan that has raised concerns for stability in the

European Union.

Political leaders urged Catalan separatists to back down and ease Spain's worst political crisis in decades, with the leader of the opposition Socialists, Pedro Sanchez, urging them to "stop everything" and respect the law.

And France said that Catalan independence would not receive international recognition.

Hundreds of thousands of Spaniards rallied Sunday in a tide of red and yellow national flags in what is the worst upheaval since the country returned to democracy in the 1970s.

Tempers have worsened over the past week after national police cracked down on voters during a banned October 1 Catalan independence referendum.

Regional president Carles Puigdemont said the vote justified secession and separatists urged him to declare independence in defiance of the central government and national courts.

Puiedemont

hinted in an interview on Sunday that the region would go ahead with the declaration if Madrid continued to refuse dialogue.

"We have said yes to so many mediation options that have been proposed,” he told Catalan television channel TV3.

"The days are going by and if the Spanish state does not give a positive response, we will do what we set out to do. ”