Northern Ireland's Chief Constable has legal authority to enter into a £180m contract for temporary support staff, a High Court judge has ruled.
Mr Justice Treacy dismissed overlapping legal challenges to the PSNI plan brought by public sector union Nipsa and the mother of a loyalist murder victim.
He said the Patten recommendations for reforming the force and law made it "abundantly clear" that a process of civilianisation and contracting out services should be undertaken.
Nipsa had claimed the deal with Resource NI to bring in staff to perform duties such as custody detention officers and call handlers was unlawful.
The validity of using private agencies to recruit was also questioned by Vivienne McCord, whose son Raymond (22) was beaten to death and dumped in a north Belfast quarry in 1997.
His murder was at the centre of a damning report by former Police Ombudsman Nuala O'Loan that established evidence that rogue Special Branch officers colluded with a north Belfast UVF gang responsible for up to 16 deaths.
Mrs McCord was seeking to stop retired RUC men being brought back to work on historical enquiries.
The joint challenges to the Chief Constable's contract with Resource claimed it was for staff functions outside the scope permitted by the Police (NI) Acts of 2000 and 2003.
In his judgment, Mr Justice Treacy said: "It is to my mind clear from the history of the governing legislation and its scheme and purpose that the Chief Constable does have the power to enter into the impugned contract for the provision of services by Resource."
He rejected the submission that engaging permanent staff by the Policing Board is the only means of securing civilian assistance, declaring it inconsistent with Patten.