SPAIN’S conservative People’s Party (PP) has been ridiculed after the leader of its group in the European Parliament wrote to fellow MEPs urging them to boycott a talk there by the Catalan president on the state’s “illegal” independence referendum.

Esteban González Pons, the PP leader in Brussels, wrote to his party colleagues calling for them to ignore the Brussels event – at which Carles Puigdemont is expected to defend the Catalan indyref, despite Spain’s Supreme Court declaring it illegal.

He said their attendance could be “used to create the false impression that the European Parliament supports this call for an illegal referendum”.

However, his Catalan opponents said his remarks showed the PP were “nervous” and “sad”.

Gonzalez Pons said the “unofficial” event was against Spain’s constitution, European legislation and the rule of law. “This independence referendum Puigdemont wants to talk about is an unconstitutional act, which goes not only against Spain, but also against the deepest principles and values of the European Union,” he said.

“An illegal act that cannot and will not occur. It would create a dangerous precedent for the unity of many other European countries.

“Fortunately, the freedom of speech is at the core of our most previous rights,” he added, apparently failing to appreciate the irony of his statement. “But there is also the right to differ and the right to raise the voice when someone pretends to cast doubts about the territorial integrity, the sovereignty and the democracy in our nations.”

He admitted that the room, which is the biggest in the building, could be full of people for Puigdemont’s address tonight, but they would be only “Green MEPs, extreme left MEPs” or “extreme right MEPs”.

The cause of independence for Catalonia, which is supported by more than three quarters of the Catalan population, is seen as Spain’s Brexit.

A spokesperson for the Diplomatic Council of Catalonia (Diplocat) laughed, then said: “Yes, it is a good way to show what the concept of freedom of speech and democracy mean to some people.

“They don’t enter in dialogue with Catalonia because they try to avoid dialogue – literally. It’s rather sad, but that’s what we have at the other side.”

Puigdemont will attend the gathering with his vice-president and economy minister Oriol Junqueras and foreign affairs minister Raül Romeva, where they will defend government plans to hold their indyref later this year.

They will outline the moves Catalonia continues to make to reach an agreement with the Spanish government to hold a legally binding poll, advances which Madrid has repeatedly rebuffed.

If Spain continues to refuse to enter into a dialogue, the trio will warn that Catalonia is determined to go ahead with the referendum.

In a position that has been compared to Scotland’s, they will explain that the state – Spain’s richest – is pro-European and aims to stay in the EU in the event of its achieving independence.

Alfonso Dastis, Spain’s foreign affairs minister, said last week that Madrid would fight “any attempt to justify what is not justifiable” in Brussels and repeated the government’s view that the proposed referendum in Catalonia was illegal.added that Madrid would make sure that foreigners understood “the legal parameters of Spain and the current situation”.