More than 140 council staff could be relocated outside the borough after Capita announced a reshuffle of its services.
Barnet Borough Council signed off its new support and customer service organisation (NSCSO) to the private firm in a contract worth £320million in August.
The contract forms part of the council’s controversial One Barnet scheme to outsource millions of pounds worth of services to the private sector.
Just two months after signing the deal, Capita has confirmed it has started a 90-day consultation period to move back-office services out of Barnet.
A total of 256 employees are involved in the consultation, although Capita has said it aims to retain around 107 of those in the borough.
A spokeswoman for the firm said: “The customer and support group partnership was set up to reduce costs and improve services to residents in Barnet.
“From the outset, we proposed moving some back-office services to sites outside the borough, investing in supporting technology and making processes more efficient.
“These changes will deliver value for money to the council and provide a better service to residents.
“No final decisions will be made on redundancies until the end of consultation period.”
Under the reshuffle people could be relocated to offices in Banstead, Blackburn, Belfast, Bromley, Carlisle, Coventry, Darlington, Sheffield, and Weybridge.
Barnet Alliance, a group of campaigners who have strongly opposed the One Barnet programme, have condemned the plans saying it will make "mass redundancies inevitable".
Barbara Jacobson, spokeswoman for the group, said: “What Capita describes as “driving towards Barnet plc and a successful London suburb” completely ignores the facts that the people losing their jobs are part of the community, that the community is not a public limited company, and that Barnet was a successful London suburb before the takeover.”