Thousands of people congregated in Barcelona on Saturday for a rally calling for a dialogue between the Spanish government and Catalan officials amid concerns that the wealthy northeastern region of Catalonia could unilaterally declare independence.

The event was held almost a week after the Catalan regional government conducted a controversial secessionist referendum in defiance of Spain’s national government and the country’s Constitutional Court, which called the referendum illegal, Efe news reported.

“Catalans do not seek division,” and “we want to talk”, were some of the slogans at the political gathering in Sant Jaume Square, situated at the heart of Catalonia’s regional capital and largest city, Barcelona.

The demonstration was not organised by any political group but it was attended by a delegation of officials from the Catalan Socialist Party, a regional branch of Spain’s principal Socialist Party opposition.

Tensions between the Spanish national government and the regional government of Catalonia skyrocketed since the banned Catalan independence referendum went ahead on October 1.

Senior Catalan officials were said to be studying a possible unilateral declaration of independence, an act that had been roundly discouraged by the Spanish government and the wider international community.

According to Catalan officials, 90 per cent of the 2.3 million people voted for independence and the turnout was 43 per cent.

Catalan President Carles Puigdemont is expected to address the Catalan Parliament on Tuesday.