Senior figures in Sinn Féin, including Gerry Adams, Martin McGuinness and Gerry Kelly, have stepped up their security in recent weeks for fear that an attempt may be made to kill them.
Dissident republicans have stepped up their violence this year by burning commercial premises and in incidents involving guns and home made bombs.
RTÉ News understands that the party's leadership believes that a number of disaffected IRA members have established contact with dissident republicans and that they are opposed to any change in Sinn Féin's policy on policing.
It is now an issue that will decide the future of devolved government in Northern Ireland.
The DUP will not go into a power-sharing administration unless Sinn Féin members are prepared to support the PSNI and the rule of law.
Gerry Adams and the Sinn Féin leadership have been finding it hard to find support within the party for a shift on policing policy.
It is now an even more serious matter for hardline republicans.
Meanwhile, Taoiseach Bertie Ahern has called on both Sinn Féin and the DUP to show more trust on the issues of policing and power-sharing ahead of the 24 November deadline for the St Andrews Agreement.
