The Catalan leadership has expressed hope that the national day on Tuesday, known as the Diada, will draw major demonstrations in support of independence as well as widespread displays of yellow ribbons, the symbol of those opposed to the jailing of Catalan politicians. Prominent figures including Pep Guardiola, the pro-independence Catalan soccer coach of Manchester City, have made public statements while wearing the ribbons.

Mr. Guardiola compared Catalans’ wearing of yellow ribbons to the show of support by Tiger Woods and other golfers toward Jarrod Lyle, a golfer who died recently of cancer.

Mr. Torra said he hoped that Tuesday’s activities would feed another upswell of support on the Oct. 1 anniversary of the independence referendum, which was marred by clashes between Spanish police officers and voters. A clear majority of those voting that day approved independence, but the government immediately declared it null and void, since the referendum itself had been illegal and the recount contested.

There is no evidence that voters have shifted their views much over the past year. An election in December yielded almost the same result as the previous one: A slim majority of separatist lawmakers won control of the Catalan Parliament, to the dismay of the national government. Madrid had hoped the vote would deal a major blow to the independence movement after months of turmoil and the announcement by many companies that they were moving their headquarters outside Catalonia to avoid political instability.

Given the region’s deep divisions, it is unclear if the demonstrations on Tuesday and next month will be peaceful. The Spanish government said last week that it would send 600 riot police officers to help Catalan security forces handle the protests and any backlash. Mr. Torra responded over the weekend that Catalonia “doesn’t need so many policemen but more infrastructure.”

In the past few months, thousands of yellow ribbons have appeared in the region’s streets and squares and on its beaches, prompting clashes between supporters and opponents of independence. In late August, Albert Rivera, the national leader of the Ciudadanos Party, removed yellow ribbons in Alella, a town northeast of Barcelona, and made a public display of throwing them in a trash bag, with some residents shouting insults and calling him a fascist.