Plaid Cymru MEP Jill Evans has co-signed a question to the European Commission condemning the actions of the Spanish government in trying to prevent Catalonia's forthcoming independence referendum.
It follows reports that Spain's prosecutor general has threatened 712 democratically elected mayors in Catalonia with legal action if they support holding the referendum.
The Catalan Parliament has passed a law to call a referendum on independence from Spain to be held on 1 October this year.
Jill Evans will be part of the official observation mission overseeing the referendum.
Jill Evans MEP said:
"Threatening elected officials with arrest for upholding a democratic decision to hold a referendum is outrageous.
"The Spanish government seems determined to disrupt a democratic referendum through intimidation.
"The government has obligations as an EU member to respect democratic decisions and the fundamental rights of all EU citizens.
"We are asking the European Commission to urgently address these issues, in particular the threats issued against elected mayors."