Multimillion-pound plans by three police forces to outsource services to the firm at the centre of the Olympics security debacle have collapsed.
Hertfordshire Police and Crime Commissioner David Lloyd said the Bedfordshire, Cambridgeshire and Hertfordshire Strategic Alliance had discontinued negotiations with G4S.
The three forces were looking in to working with G4S in a bid to save £73 million by outsourcing support functions.
The proposals involved switching 1,100 roles, including human resources, IT and finance to the security contractor.
But doubts were raised after the company was forced to admit severe failings over the Olympics security contract last summer, which led to police officers and 3,500 extra troops being deployed to support the operation.
In a statement, Mr Lloyd said: "I have always said that I would make my decision once the evidence was received and assessed.
"It is now clear that the G4S framework contract through Lincolnshire Police was not suitable for the unique position of the three forces."
But he added that outsourcing to other companies would still be considered.
Mr Lloyd said: "I am already in discussion with other market providers and will continue to talk with G4S about how they can assist policing support services in Hertfordshire. My clear position is that all elements of support work will be considered for outsourcing or other use of the market.
"I made my decision based on evidence and on the recommendations from the Chief Constables. I still believe that substantial elements of policing support services will be best delivered by the private sector and will ensure that this option is immediately pursued.
"We will now move forward looking at organisational support services, as before."
Police and Crime Commissioner for Bedfordshire, Olly Martins, said: "The concerns that I had about this proposal are on record but I am pleased that following the evaluation and subsequent discussions, the three Police and Crime Commissioners have ended up in agreement with a shared view that this contract does not deliver what we need.
"However, we do still have to save money. Strengthening the ways in which we collaborate with Hertfordshire and Cambridgeshire is a crucial element of our on-going investment in all our police services.
"I now look forward to working with my fellow commissioners to develop new and innovative ways in which we can progress our collaborative approach."
The force's Chief Constable Alf Hitchcock said: "As an Alliance we have been working together to explore a range of options for making savings at a time when all three forces are facing significant financial challenges.
"Along with my Chief Constable colleagues in Cambridgeshire and Hertfordshire and the three commissioners, we are continuing to explore other opportunities, whilst in Bedfordshire we are using the Option 10 and Lean processes to achieve savings in-house and protect front line policing."
Kim Challis, chief executive of G4S Government and outsourcing solutions, said: "We have put forward a compelling proposition to the police forces of Bedfordshire, Cambridgeshire and Hertfordshire which would have guaranteed them savings of over £100 million over the next ten years, allowing them to meet the financial challenge of the Comprehensive Spending Review without compromising on efficiency or public safety.
"Our proposition was to operate back office services at the volume and scale required to deliver significant savings to forces, enabling them to concentrate their resources on frontline roles: it was never about replacing police officers. This has already proved to be the case in Lincolnshire, where we have a successful partnership which, in less than a year, has seen us deliver savings in running costs of around 16%.
"We continue to work with a number of signatory forces on the Lincolnshire Police contract, including Hertfordshire, to see how we can help them to generate the savings they need."
Chief Constable Andy Bliss, of Hertfordshire Constabulary, said: "My focus remains on continuing to fight crime and deliver a great policing service, yet dealing with the challenge of making significant savings.
"I shall be working very closely with David Lloyd, the Police and Crime Commissioner, as we now look at all possible options to ensure that we jointly maximise the efficient use of every pound spent on policing in Hertfordshire."