The DUP's security spokesman has criticised plans by the Policing Board to replace armed guards at police bases in the north-west with unarmed civilian personnel.
Mr Gregory Campbell MP has described the move as deeply worrying, but the plan has been defended by the board's vice-chairman, Mr Denis Bradley, who said it was part of the board's policy of putting more uniformed officers on the streets.
The plan is to be implemented at PSNI stations at Maydown and Strand Road in Derry, and at stations in Strabane, Coleraine and Limavady over the next three months.
Security firms which provide civilian staff to the PSNI and to the Northern Ireland Office have been asked to make available 20 employees for the scheme, 10 of them Catholics and 10 Protestants.
It is believed those selected for the scheme will undergo a vigorous vetting procedure before they receive final security clearance to work in sensitive security installations.
Confirming the move, a PSNI spokesman said the policy of civilian security guards working alongside armed police officers is to be "examined in closer detail" over the next three months.
"The use of civilians in such roles is consistent with the PSNI's commitment to a greater use of civilians while at the same time releasing more police officers for front-line duties. Where civilians are employed on guard duties, they will always work alongside an armed police colleague", the spokesman said.
However, Mr Campbell said because the north-west was the hotbed of dissident Republican activity in recent months, civilian security guards would be more vulnerable to attacks.
"If the Policing Board are going to go looking for people to do this job and tell them they will be unarmed, I would imagine there will not exactly be a queue coming, particularly from the Catholic community, to make up the 50/50 recruitment policy."
However, the Policing Board's vice-chairman, Mr Bradley, said the scheme was aimed at putting more police officers on the streets.