The Irish government must do more to encourage nationalists to join the PSNI, a former Policing Board vice-chair has said.

Denis Bradley called for political leaders in Dublin to “claim the PSNI” as their own, and challenged them to carry the message into the heartlands of nationalism in Northern Ireland.

Mr Bradley said the recent data breach, which saw the details of 10,000 police officers and staff accidentally posted on a website, went beyond a security issue.

It has led to fears that Catholics may be discouraged from signing up to the PSNI.

Writing in Saturday’s Irish Times, Mr Bradley accused dissident republicans of holding the people of Ireland “to ransom”, saying that as a result, the PSNI has not embedded itself into the nationalist community, more than two decades after its formation.

Mr Bradley served as vice-chair of the Policing Board between 2001 and 2006, covering the early years of the PSNI.

He cited the influence of the late Martin McGuinness, who encouraged nationalist support for the PSNI after Sinn Fein signed up to policing following the 2006 St Andrews Agreement.

In 2009, Mr McGuinness condemned dissident republicans as “traitors to the island of Ireland" after the murder of police constable Stephen Carroll.

Writing in the Irish Times, Mr Bradley said dissidence was “an Irish problem that has cascaded down the generations, and bringing it to a resolution needs all the attention and authority of the Irish people and their Government”.

He wrote: “The Irish Government must now claim the PSNI as its own. To make it clear that to kill or injure a PSNI officer is the same as killing a Garda.

“They must launch a campaign to encourage young nationalists, North and South, to join the PSNI.

“They must challenge all the other parties in the Dáil to join them as they encourage and challenge all institutions and organisations, from the GAA to the Catholic Church, in promoting that message.

“They must deliver that message in the heartlands of northern nationalism, where the dissidents have a small foothold and where the people still carry the memory and the fear of the gun.”

Mr Bradley said people should be reassured that violence, not the British people, is the obstacle to “a shared and reconciled Ireland”.

He added: “Finally, in issuing the ultimatum, they must acknowledge the complexity and tragedy of Anglo-Irish history and must acknowledge that a similar agreement to that offered to the Provisional IRA and the loyalist groups will ultimately be offered to those dissident prisoners who are in jail, North and South.”

Earlier this week, Archbishop Eamon Martin asked Catholics to support the PSNI in the wake of the data breach crisis.

Archbishop Martin said: “I have previously encouraged young people from the Catholic community to consider a career in policing. Today I reiterate this sentiment.

“For that reason I also call on everyone in the community to reject entirely those who would intimidate or threaten the courageous women and men – including those from the Catholic community – who selflessly choose this noble vocation of policing.”