A referundum is a vote which allows all the citizens to approve or to reject a measure proposed by the executive power. The referendum is thus an instrument of " direct democracy ". It allows the people to intervene directly in certain domains of the national or local politics. Today, many observers suggest resorting to more referendum such as the Brexit referundum. In the UK, there are also some ‘top-down’ referendums with the citizen initiated ballots which has also been seen in many US states and elsewhere.