The European Commission is looking into what happened to the Spanish version of a written answer from Commission President Jean-Claude Juncker to a Spanish MEP earlier this week, which differed considerably from the original answer given in English.

Catalan centre-right MEP Santiago Fisas had asked Juncker in a written question whether or not the European Commission would recognise a potential call for a unilateral declaration of independence from Catalonia, or if it would respect the Spanish Constitution, which is against such a declaration.

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The Spanish translation of the original English version adds an extra 9-line paragraph saying that a regional parliament cannot decide on the fate of its territory.

Fisas' question for Juncker came just days before Catalans head to the ballot box on Sunday (27 September) in a regional election that has turned into a de facto referendum on independence from Spain.

"There is only one authentic version," Commission spokesperson Mina Andreeva told journalists on Thursday (24 September).

"The answer to the question that was given in English is the authentic version because it is the English version to which the President agreed and which bears his signature," she added.

She said that "mistakes" and "human errors" do happen in an organisation like the Commission of 35,000 people. "And as always when human errors happen, we look into our system, how it works and we are trying to establish the facts", she continued.

"I think what is important, is to know that nobody can manipulate the Commission", Andreeva insisted once again.

However, while the English version is short and simple answering that "it is not for the Commission to express a position on questions of internal organisation related to the constitutional arrangements of a particular Member State", the Spanish version adds an extra 9-line paragraph, saying that a regional parliament cannot decide on the fate of its territory.

"Determining the territory of a Member State is only set by national constitutional law, and not by a decision of a regional Parliament contrary to the constitution of this State", it says, referring to the Treaty of the European Union.

More than a mistake

Catalan liberal MEP Ramon Tremosa believes that the extra paragraph is a manipulation of the Spanish government. "It is a manipulated paragraph, it is not a human error, it is more than a mistake."

"If the European Commission does not bring out the truth, it will have lost a lot of credibility," Tremosa said, adding that the Spanish Foreign Minister José Manuel García-Margallo has already used the extra argument from the Spanish version in a televised election debate in Catalonia.

Juncker made headlines across Spain on Monday with the Spanish version of the answer, just days before the regional election in Catalonia.

Independence is the main talking point surrounding Catalonia's vote on Sunday, with the regional election becoming a plebiscite on Catalan secession from Spain.

Opinions from the European Union could have an impact on how people vote.

It was not possible to get a comment from MEP Santiago Fisas. However, in a radio interview on Ser Catalunya on Wednesday, Fisas said that he had only seen the Spanish version of the answer and that no one had informed him of any change.

Once that happens he said he would "write a letter to Mr Juncker asking for explanations."

The case came to light when an assistant to liberal MEP Ramon Tremosa - Aleix Sarri - happened to take a look at the English version and realised that it looked very different than the Spanish version. Both answers to the MEP question have since been taken off the European Parliament website, while the incident is being investigated.

The standard answer

Both versions of the Juncker answer refer to a previous answer by Juncker on a similar question, which in turn refers to three previous answers by the European Commission on other related questions.

One of those three answers finally refers to a reply from 2004 by former Commission President Romano Prodi which is the European executive's standard response to questions of what will happen if a region of a member state becomes independent. The Commission argues that in that case, a new independent country becomes a third country and must reapply for EU membership.

However, none of the abovementioned Commission answers in English mention whether or not a regional parliament can decide on the fate of its territory, as the extra paragraph in the Spanish version said was against the Treaty of the EU's "article 4, paragraph 2".