As a result of the principle of royal sovereignty, bills are validated through royal accent. However, the Queen acts on the advisement by the Prime Minister of the United Kingdom. The Queen also has the right to dissolve parliament. This royal right was last exercised in 1999. Most Members of Parliament declare their allegiance to one of the three main political parties. After a general election, the Leader of the party with most Members of Parliament is asked by the Queen to become Prime Minister who then forms a government to manage the country.