BRITISH prime minister Theresa May has signed the paperwork to trigger Article 50 of the Lisbon Treaty, setting the clock to run on the UK's exit from the European Union.
Ambassador for the EU, Tim Barrow, will present the formal notice to Council of Europe president Donald Tusk today (Wednesday), which will officially be the first day of the two-year countdown.
The UK will now begin negotiations with the remaining EU-27, but despite anticipation on either side of the Channel, this does not automatically include trade agreements and how to handle movement of people: Article 50 is designed to start a process of settling debts, and does not cover anything to do with the outgoing member State's future relationship with Europe.
This means neither side is obliged to discuss or try to agree any measures to protect Brits living in EU countries, the highest number of whom are in Spain.
Neither does it mean Britain is required to make decisions about the hundreds of thousands of EU nationals living in the UK, of whom an estimated 100,000 are Spanish.
They include a sizeable Galician diaspora who moved to Britain in the 1950s, and surviving Civil War evacuees from all over Spain, as well as adults of all ages who have lived there for anything from a few months to 20 or more years.
Spaniards in Britain have the option to apply for UK citizenship after five years of residence, and joint nationality is available, but the situation for Brits in Spain may be very different.
Firstly, Spain only offers joint nationality to citizens of its former colonies, who can apply for dual or full citizenship after two years of residence, whilst everyone else has to prove 10 years of continuously living in the country.
Additionally, many Europeans in Spain – particularly pensioners and those living in 'expat belts' – speak little or no Spanish, which would preclude them from applying.
In practice, citizenship requirements are not very demanding – a multiple-choice quiz on aspects of legal, cultural, geographical and political life, and a test to prove Spanish language ability of level A2, equivalent to a good GCSE grade, are the only requisites besides not having a criminal record.
This is not impossible to study for from scratch in two years, and many town councils offer free Spanish classes.
But not everyone wants to apply for British or Spanish citizenship respectively, and many fear that doing so could cause problems for them if they need to spend an extended period in their native country, such as for caring for a family member.
Read more at thinkSPAIN.com