A formal consensus over policing in Northern Ireland has become a realistic possibility after Sinn Fein agreed to hold a special party conference on the issue next month.

The party will vote on whether to support the Police Service of Northern Ireland (PSNI) at January’s ard fheis after two-thirds of delegates supported leader Gerry Adams’ motion.

Sinn Fein has traditionally opposed the PSNI and its predecessor the Royal Ulster Constabulary because of a perceived Protestant bias.

After six hours of talks in Dublin, Mr Adams said next month’s conference would help to ensure that the police “never again do to our people what they did before”.

The decision has been broadly welcomed by Downing Street and the Democratic Unionist Party (DUP), while Irish taoiseach Bertie Ahern said the move was “clearly a landmark” and a “defining moment in the peace process”.

“A successful outcome is vital to the continuing success of this process. And, of course, it will also make a real difference to the daily lives of many people across both communities in Northern Ireland affected by crime and other issues which only the police can properly address,” the Irish prime minister said.

Policing in Northern Ireland has long been regarded as one of the thorniest issues standing in the way of the peace process, with assembly elections due to be held in three months time.

Speaking ahead of yesterday’s announcement, Northern Ireland secretary Peter Hain said: “Getting agreement on policing and power sharing are the twin pillars on which devolution will stand and I am very encouraged that what we all have been working for is moving into place.”