The issue is important because the king is obliged to authorise all marriages of people in the line of succession. Otherwise they lose their place. This is what happened to Prince Amedeo when he wed the socialite Elisabetta Maria Rosboch von Wolkenstein. Prince Amedeo is the son of King Filip's sister, the Princess Astrid. He is sixth in the line of succession to the throne of the Belgians.
Prof Hendrik Vuye, an expert in constitutional law, writes that it says a lot that nobody is bothered about the fact that the king has taken an unconstitutional decision. He too stresses that it's not about Prince Amedeo, because the chance he would succeed is virtually nonexistent.
Wed on 5 July 2014 Prince Amedeo asked his uncle for permission on 20 September 2015. This was granted on 12 November of the same year by a royal decree signed by the prime minister and the justice minister. A spokesman for Prime Minister Michel insisted that all the present government had done was to regularise the situation.