Spain's Prime Minister Pedro Sanchez holds a year-end news conference after the weekly cabinet meeting at Moncloa Palace in Madrid, Spain, December 28, 2018. REUTERS/Susana Vera

MADRID (Reuters) - Spanish Prime Minister Pedro Sanchez sought on Friday to reassure Britons living in Spain, saying their rights would remain unchanged after Britain’s exit from the European Union.

The government was working on measures to ensure Spain-based Britons would keep their rights even if Britain crashed out of the EU without a deal on March 29. Measures were however conditional on Spaniards getting the same treatment in Britain, he added.

“Their rights will be preserved whatever the scenario,” he told the prime minister’s traditional end-of-year news conference.

Spain is the most popular European retirement destination for Britons and is home to around 300,000, mostly settled on the coast. Among foreign nationals, they are by far the biggest users of Spain’s state-funded, universal health care system.

Sanchez said he would by February present a law outlining the rights of citizens in the respective countries that would also lay out measures to protect bilateral commercial relations.

Spanish flag-carrier Iberia risks losing its right to operate in the European Union after the European Commission said airlines falling below the 51 percent threshold for EU ownership will not be able to operate in Europe in the event of no deal.

Iberia is owned by International Airline Group (IAG), which is also the parent of British Airways.