that year to a five-year waiting period before they were eligible to register as citizens, due to concerns over the frequency of marriages of convenience. Children born overseas to Maltese mothers between 21 September 1964 and 1 August 1989 also gained eligibility to register as citizens with no requirement to reside in Malta. Abandoned children found in Malta could not acquire Maltese citizenship after the 1989 amendment due to the requirement for a Maltese parent; the 2000 changes addressed this oversight by granting such individuals citizenship until their eligibility to another citizenship could be established. Further reforms in 2007 extended eligibility for citizenship by descent to children born overseas to Maltese citizens who were not born in the country. Individuals with a Maltese-born lineal ascendant who died before 1 August 2007 and who themself had a parent born in Malta may acquire citizenship by registration. Maltese citizenship can be continually transmitted through each generation born abroad provided that each subsequent generation is registered for citizenship. Individuals who were unable to claim citizenship before their qualifying parent's death are exceptionally eligible to register if their parent's death was before 1 August 2010. Under the citizenship provisions of the Constitution at time of independence, a CUKC born abroad became a Maltese citizen only if their father and a paternal grandparent were born in Malta. The 2007 amendment extended citizenship to former CUKCs born overseas with a Maltese-born mother and maternal grandparent. European integration Malta joined the European Union as part of the EU's 2004 enlargement. Maltese citizens have since been able to live and work in other EU/EFTA countries under freedom of movement for workers established by the 1957 Treaty of Rome and participated in their first European Parliament elections in 2004. Before the UK's withdrawal from the EU in 2020, Maltese citizens held a particularly favoured status there. While non-EU Commonwealth citizens continued to need a residence visa to live in the UK, Maltese citizens were able to settle there and immediately hold full rights to political participation due to their status as both Commonwealth and EU citizens. Maltese citizens (along with Irish and Cypriot citizens) domiciled in the UK were able to vote in the 2016 United Kingdom European Union membership referendum while all other non-British EU citizens were not. Citizenship by investment Amendments to the Maltese Citizenship Act in 2013 provided the legal basis for the creation of the