BARCELONA, Spain (AP) — The Latest on Catalonia's referendum on whether to break away from Spain (all times local):

1 p.m.

Catalan officials say that mail-in voting by residents living abroad has already started in an independence referendum that Spain's central government says is illegal.

Catalonia's regional foreign affairs chief Raul Romeva says "the referendum has already started."

Romeva says that "the Catalan community that lives abroad has already started to vote." He didn't elaborate.

Catalans registered as permanently living abroad can request a ballot by mail.

Regional president Carles Puigdemont says that if the "Yes" vote wins in the Oct. 1 vote, "we will have won the right to be listened to" by the European Union.

Spain's constitutional court has suspended the Catalan referendum law and the decree calling the vote, while it considers the central government's claim that it's unconstitutional.

10:55 a.m.

Hundreds of thousands are expected to rally in Barcelona to show support for an independent Catalan nation and the right to vote in a controversial referendum that has been banned by Spain.

Monday's rally falls on National Catalonia Day, which is celebrated annually. But this year, it comes amid deep social and political division over the Oct. 1 vote.

Polls show most Catalans support a referendum but are roughly divided over splitting from Spain.

Most Spaniards reject it, and Spain's constitutional court has ordered the vote suspended. But the Catalan government has vowed to hold the referendum and be bound by its result to either declare independence or call regional elections.