 STUK may interrupt the operation of a nuclear power plant if so required in order to ensure safety.A cabinet decision in 2002 to allow the construction of a fifth nuclear reactor was accepted in parliament.The Green League, which was principally opposed to the expansion of nuclear power and which held the position of the Minister of Environment, left the coalition government on 31 May 2002 in protest of the cabinet's decision, narrowing the majority of the coalition in the parliament.