Pressure is mounting on Herfordshire Constabulary's plans to hand back its office functions to beleaguered security giant G4S after another political party threatened to veto the deal.

Hertfordshire’s Liberal Democrat party has said it would throw out proposals to outsource to G4S if it wins the police crime and commissioner election in November.

The move comes after Labour’s candidate for the £75,000-a-year role, Sherma Batson, said she would block all outsourcing of police services if elected.

The Conservative candidate, David Lloyd, widely considered to be the frontrunner, said he would still consider the G4S deal, despite the fiasco caused by the company failing to supply enough security staff to the Olympic games.

Speaking today, Chris White, the Lib Dem police spokesperson, said: "The astonishing news that Herts, Beds and Cambridgeshire constabularies will be pressing ahead with this privatisation is likely to lead to a collapse in public confidence in policing in the three counties.

"Even before the Olympics fiasco, the record of G4S was questionable. Policing is a public sector service and should not normally be handed over to private companies - especially private companies which are known not to deliver.

"I don't want to see the army being called in to Hertfordshire to perform basic policing."

Hertfordshire, Cambridge and Bedfordshire police forces are all planning to hand functions such as human resources, finance, ICT, procurement and corporate communications.

The final decision over the proposals has been delayed due to concerns raised over G4S by the problems at the Olympics, which saw the army and officers from forces including Hertfordshire scrambled to sure up security at the games.

This means it will be decided by whoever becomes the county’s first elected commissioner after the November 15 election.