another change in the law. This proposal would have given nationality by origin (descent) rather than by naturalisation to the grandchildren of Portuguese citizens but it was rejected. In 2013, members of the PSD tried to pass a similar measure again but due to the political and economic crisis that engulfed the country, no vote was ever taken on the measure. Portuguese nationality regulation A number of decrees have been issued by Portuguese governments implementing the terms of the nationality laws. These include Decreto n.º 43090 of 1960, Decreto-Lei n.º 322/82, and Decreto-Lei n.º 237-A/2006 of 2006. These regulations are amended as needed; the 2006 regulations were amended in 2013, 2015, and 2017. Acquisition of citizenship Any person born in Portugal automatically receives citizenship at birth if at least one parent is a Portuguese citizen. Individuals born in the country to non-citizens acquire citizenship at birth if at least one parent has been resident in Portugal for at least one year prior to the time of birth, or was themself born in Portugal and resident in the country at the time of birth. Stateless children born in the country automatically become citizens with no further requirements. Children born overseas to a Portuguese parent are eligible to acquire citizenship by descent if their births are registered at a Portuguese diplomatic mission or if they register as citizens at any later point. Grandchildren of Portuguese citizens may also acquire citizenship by descent with additional requirements; they are required to formally declare their intention of becoming Portuguese, prove substantial ties with the nation, and register their births in the national registry. Adopted children of Portuguese citizens automatically acquire citizenship on completion of the adoption process. Foreigners over the age of 18 may become Portuguese citizens by naturalisation after residing in the country for more than five years and demonstrating proficiency in the Portuguese language. Any person convicted of a crime resulting in imprisonment for more than three years or who otherwise presents a threat to national defence is barred from naturalising. Non-citizen minors born in Portugal who meet the language and behaviour requirements are eligible for naturalisation provided that they have also completed at least one cycle of domestic primary or secondary education and have at least one parent who has resided in the country for the previous five years, regardless of their legal residence status. All other non-citizens born in Portugal to