Raul Romeva doesn't know the answer to my question. Are you going to end up in handcuffs, I ask Catalonia's foreign minister. "I don't know, to be honest," he replies. "But, in any case, that would be the worst response."

The veteran campaigner is in Edinburgh to watch this week's Holyrood elections and to catch up with his Scottish allies. But he does so as he and fellow members of his "transition government" in Barcelona face political foes in Madrid who prefer the courtroom to the ballot box.

Romeva calls this "judicialising the conflict" between what he sees as the two Iberian nations of Spain and Catalonia and what his opponents see as a state and its richest region. It is a tactic, he tells me over tea on the Royal Mile, that should have European leaders questioning whether Spain is a full democracy.

"There are still some cases pending," he says, referring to legal actions launched against the former president of Catalonia for organising a mock referendum in Catalonia shortly after Scotland's. "What are they going to do?

"What is really worrisome is the fact that in the state of the European Union you lack basic separation of powers. "The use of the judicial system as an instrument of the executive is something that should worry people everywhere. Certainly this worries us. You can’t solve a political problem in the courts...This is not the solution for anything."

Pictured: Catalan Foreign Minister Raul Romeva

HeraldScotland:

Spain - and its current caretaker government led by Conservative Mariano Rajoy - insists on seeing the Catalan drive for independence as a legal problem. Spain's constitution, put simply, does not allow any region to break away. So the courts block laws in Catalonia and try to prevent Romeva's government, formed after an alliance of pro-independence parties won elections last year, from moving towards independence.

What Romeva - a former Green MEP - and his current president, Carles Puigdemont, want is a Scottish-style vote. With the current government of Rajoy and its main opposition parties resolutely opposed to such a referendum, it looks unlikely to take place.

He said: "Using the judicial system to make politics is discrediting the whole rule of law in the Spanish administration. That is a mistake.

"You cannot consider you are in a full democracy when you simply deny the reality that you have a huge majority of people in Catalonia asking you for the right to vote."

Romeva is in Scotland on what he describes as a private visit. It was previously billed as an official one in the Catalan press. A Spanish newspaper suggested Scottish ministers had been told that there would be consequences if they met with Romeva, who styles himself as "foreign minister" but even this is a point of legal and semantic dispute.

In the end the issue of his visit was moot: elections meant Scottish officials were too busy for a formal meeting.

But his trip to Edinburgh was part of a broader Catalan international charm offensive to convince EU and other countries that their dispute with Spain may need some outside help to be resolved. The issue, including Spain's democratic credentials, he says, "should be taken very seriously by the international community and notably by European Union states. That is the message I am delivering. There is a problem."

Scottish politicians, nationalist and unionist, have offered to mediate between Catalonia and Spain. "We would be happy for help. We are asking for somebody to help us to sit at the table with the Spanish government to talk about this. We have failed so far. That is incredible.

"What we want to do is what Scotland did. The trouble is that we need someone to play Cameron’s role in Spain. But such a person does not exist. The difference between the Catalan situation and Scotland's is the democratic tradition that the UK has. That democratic tradition is very much lacking in the Spanish political structures right now. That is one of the reasons why the Catalan situation has to be seen in a very different way."

HeraldScotland:

But Romeva does not see Scotland's experience with the UK as entirely rosy. Asked what was best about the Scottish referendum, he cites the fact that it took place at all. Asked what was worst, his answer is straightforward: Project Fear.

He explains: "The worst thing about Scotland - and it happens in Spain and Catalonia too - is the use of arguments that are simply wrong. I very much deplore the fear campaign. Provoking fear is not something that strengthens democracy.

"If you have good arguments you don’t need to scare people. In the Scotland debate, people were told 'you will be expelled from EU and impoverished and you will lose anything'. We need to learn from that."