<P> This procedure is viewed by some critics as too slow and ineffective . There are voices in Bulgaria to remove the institution of Great National Assembly, which they view as an anachronism and to adopt a new procedure of constitutional amendment through popular vote . </P> <P> Passage of a constitutional act in the Czech Republic can only be accomplished through the agreement of three - fifths of all Deputies and Senators present at the time the proposed act is laid before each house of Parliament . It is the only type of legislation that does not require the signature of the President to become law . Furthermore, it is the only type of legislation the President cannot veto . </P> <P> The Constitution of Denmark provides an example of multiple special procedures that must be followed . After an amendment has been approved by parliament, a general election must be held; the new parliament must then approve the amendment again before it is finally submitted to a referendum . There is also a requirement that at least 40% of eligible voters must vote at the referendum in order for an amendment to be validly passed . </P> <P> The Constitution of Estonia can only be modified by three - fifths majority in two successive complements of Parliament, and a referendum for certain chapters . </P>

The major reason for a nation to have a written constitution is