Catalonia's President Artur Mas is hoping to secede from Spain within 18 months by calling for an early election in the region.

In a speech in Barcelona's Fòrum Auditorium in front of 3,000 people, Mas said the only way to achieve independence in the immediate future was by allowing citizens to "decide on their own collective future as a nation" as the "the Spanish State has let us down".

He slammed the Spanish government's attitude to Catalonia over the last two years, and said Prime Minister Mariano Rajoy's comments over pro-independence demonstrations being "silent majorities" were "paradoxically ignoring the absolute majority at the Catalan Parliament that supports Catalonia's right to self-determination".

Mas added that the "public consultation process" on 9 November showed that Catalonia had become "an adult country", adding that it "was not underage any longer".

The leader of the centre-right Convergence and Union alliance also called for foreign states to take part in the mediation process between Catalonia and the Spanish government.

On 9 November, nearly 80% of Catalans opted to secede from Spain in the "undercover referendum".

Catalonia is widely viewed as the industrial and commercial hub of Spain, and pays far higher taxes than any other regional community.

It accounts for over 20% of Spain's GDP, and only 8% is ploughed back into it by the state. The Catalan community represents 16% of the total Spanish population.

Following the consultation earlier this month, the Spanish government launched a lawsuit against Mas for "disobedience and dishonesty", accusing him of flouting a court injunction that prevented him from holding a vote on secession.

The court case could also prevent Mas and his deputy, Joana Ortega, from running in the next regional elections, due to be held late in 2016, as it could led to a ban from public office.