Spain could grant citizenship to millions of people with no requirement to ever live in the country, in what is set to become one of the largest expansions of voting rights in modern European history.

More than 2.5 million people have already applied under Spain’s ‘grandchildren law,’ which allows descendants of those who left the country during the Civil War and the dictatorship of Francisco Franco to claim nationality.

According to figures collected up to February 28, Spanish consulates have received 2,560,193 applications. So far, 531,297 have been approved and only 7,032 rejected. The rest remain under review.

If approval rates hold, Spain could eventually grant citizenship to a group equivalent to nearly 5% of its current population—an expansion unmatched by any recent nationality process in Western Europe.

The law, adopted in 2022 and extended until October 2025, also extends beyond the Civil War to children of Spanish women who lost their citizenship after marrying foreigners under older laws.

Unlike standard immigration routes, applicants do not need to live in Spain before becoming citizens. They are granted nationality directly and, once registered, can vote in Spanish elections.

So far, 292,944 new citizens have completed registration and, if adults, are now eligible to vote in Spanish general, European, and local elections.

The immediate electoral impact, however, is likely to be more limited than some political claims suggest. Most of the new citizens live abroad and will be included in Spain’s overseas electoral register, known as the CERA.

Turnout among Spaniards abroad has historically been low, at around 8% in recent elections, and many of the new citizens are minors or elderly. According to the media, most applicants are primarily interested in obtaining an EU passport rather than becoming active in Spanish politics. Spanish citizenship gives them the right to live and work anywhere in the European Union, making it especially attractive in countries with large Spanish-descendant communities.

The overwhelming majority of applications come from Latin America. Argentina alone accounts for more than 233,000 approved applications, followed by Cuba, Mexico, and Chile. These were among the principal destinations for Spanish emigrants during the 20th century.

Even a modest rise in turnout could prove decisive. In Spain’s electoral system, a few thousand overseas votes have often been enough to decide a parliamentary seat in smaller provinces. With several hundred thousand additional citizens potentially joining the electoral roll, that influence could grow in tightly contested elections.

The Spanish government has not published detailed estimates of how many of these new citizens are likely to vote, nor a full breakdown of the more than two million applications still pending. That lack of transparency has fuelled criticism from the opposition, particularly as it comes alongside other recent measures expanding the number of foreign nationals eligible to remain in Spain.

Spain’s “grandchildren law” is no longer simply a measure about historical memory. It is now one of the largest expansions of citizenship and voting rights in modern Europe—and could shape the outcome of the 2027 general election.