Al Jazeera's Sonia Gallego, reporting from Barcelona:

"People here would be in agreement with what Rajoy has said. They very much feel that Catalonia is a part of that and so they've gathered a lot of nationalistic fervour here.

Even though this was organised by a centre-right political party and a civil organisation, there are elements of right-wing organisations and people with right-wing sympathies as well.

Crowds here have been calling for the Catalan President Carles Puigdemont to be put into prison. It just goes to show the level of anger that they have towards the president and the secessionist point of view.

The invoking of taking full control over Catalonia has been a topic that has been discussed quite recently. It's not an automatic decision, they would have to follow a process where the Spanish government in Madrid would have to ask the Catalan president what he intends to do.

If he refuses to back down from the whole question of secession, then that's when the Spanish government would go to the Senate to invoke those emergency control powers.

That would be just one element of a situation which has been really going up to the point of brinkmanship here.

Each side has been hardening and the people left in the middle of this, many of whom feel distraught at the way that this whole situation has exploded, feel very much that their voice hasn't been heard.

They are the ones that are calling for dialogue and this is the voice that has been heeded by the mayor of Barcelona.

That dialogue has to be the way that this situation, this crisis needs to be resolved."