However, no act by the President of the Republic is valid or executed without the countersignature of the appropriate minister with the exception of certain acts specified in the Constitution in article 35 paragraph 2. The government of the country is based on the parliamentary system. The government must have the confidence of the Chamber, i.e. the majority of the deputies elected by the people by direct, catholic and secret vote. Every Greek citizen, who is legally entitled to vote and has reached the age of 25, can be elected as a deputy. The Chamber is elected every four years by general election.
Law establishes the number of deputies.
The present-day Chamber consists of 300 deputies. Of the 300 seats, ten are reserved for state deputies who are elected by each party. The number of such deputies from each party is governed by the percentage of the total vote gained by the party. The country's electoral system is established by law, as are the electoral districts. The number of deputies for each district is laid down by presidential decree on the basis of the population of the district.