London: Northern Ireland First Minister Peter Robinson stepped down from the power-sharing government over the political crisis linked to the Irish Republican Army (IRA).
Robinson is the leader of the Democratic Unionist Party (DUP). He announced his resignation on Thursday after his party failed to win support in a vote to suspend the assembly, reported Xinhua news agency.
The leader wanted an adjournment to allow crisis talks to take place over allegations that the IRA still exists, and the fact that one of its ex-members, Kevin McGuigan, was killed last month.
Detectives on Wednesday arrested three senior IRA members as part of the murder inquiry. One of the three was Bobby Storey, the Sinn Fein party`s chairman in Northern Island Assembly.
However, Robinson`s proposal was rejected by the Sinn Fein, the SDLP (Social Democratic and Labour Party) and the Ulster Unionist Party (UUP).
Arlene Foster, the minister for finance and personnel of DUP will now become acting first minister.
"In light of the decision by republicans, nationalists and the UUP to continue with business as usual in the Assembly, I am therefore standing aside as first minister and other DUP ministers will resign with immediate effect with the exception of Arlene Foster," said Robinson.
"The prime minister is gravely concerned about the situation. As he was saying in the House on Thursday that he want to see all politicians in Northern Ireland working together" a spokeswoman of Prime Minister David Cameron said.
"There are different people calling for different things, and the prime minister`s calls with the secretary of state and the first minister are an opportunity for us to consider what steps should be taken next," she said.