A “critical” overhaul of the communications network used by Britain’s emergency services is likely to be hit by further delays and cost £3.1bn more than the original budget.
The National Audit Office (NAO) has questioned if the replacement for Airwave will meet its target date of 2022, while the Home Office predicts the final cost will be £9.3bn.
The Home Office had already pushed back the introduction of the Emergency Services Network (ESN) by three years.
But the NAO reports raises doubts about the revised date, and also says key technology for ESN is not yet proven in “real world conditions”.
It concluded that the Home Office’s management of the programme has led to delays, increased costs and poor value for taxpayers.
Sir Amyas Morse, head of the NAO, said: “The success of the Emergency Services Network is critical to the day-to-day operations of our emergency services that keep us all safe.
“The Home Office needs a comprehensive plan with a realistic timetable that properly considers risks and uncertainties.
“It has already been through one costly reset and is in danger of needing another unless it gets its house in order.”
Since 2000, emergency services have communicated using a dedicated digital radio network known as Airwave.
It is used by all 107 police, fire and ambulance services in England, Scotland and Wales, for communications between control rooms and teams in the field, as well as 363 other organisations such as local authorities and train operating companies.
In 2011, the Home Office decided to replace Airwave with ESN.
The new service is intended to match Airwave in all respects, allow users to take advantage of high-speed mobile data and save money by sharing an existing commercial 4G network.
It had been expected that emergency services would start using ESN in September 2017, with the transition being completed at the end of this year.
But the NAO said that by 2017, the Home Office realised its plan was not achievable.
Last year the department announced a “reset” of its approach, based on a phased introduction of ESN services, rather than launching the whole programme at once.
The new plan is for Airwave to be switched off in December 2022.
But the NAO’s report said: “There are still significant risks and, based on past performance, it seems unlikely that ESN can be delivered by the target date of 2022.”
The Home Office now predicts that ESN will cost £9.3 billion, £3.1 billion more than the sum forecast in 2015.
Of this rise, £1.4 billion is the cost of extending Airwave, £0.5 billion is an increase in contingency and the rest of the programme is now forecast to cost £1.2 billion more.
The NAO described the revised forecast costs as “highly uncertain”.
Technology needed to allow emergency services to communicate effectively using ESN is not yet ready, according to the watchdog.
It said aircraft are currently unable to receive the signal needed to communicate with those on the ground and devices are unable to communicate directly with one another without a network signal.
The NAO acknowledged that the Home Office’s reset has addressed some of the programme’s issues by adopting a staged approach to the roll-out, replacing a key piece of technology, strengthening management teams and processes, and re-negotiating contracts.
While ESN is expected to be cheaper than Airwave in the long-run, savings will not outweigh costs until at least 2029, the report found.
It concluded: “To date, the Home Office’s management of this critical programme has represented poor value for money.”
Meg Hillier, chairwoman of the Public Accounts Committee, said: “The Emergency Services Network is to be used by police, firefighters and ambulance crews for the communications they need to do their life-saving jobs.
“The Home Office must take an urgent and honest examination of its ability to deliver to its new schedule for this critical project.”
A Home Office spokeswoman said ESN is “on track to deliver an ambitious, world-leading digital communications network for the emergency services by 2022, resulting in savings of £200 million a year”.
The spokeswoman said: “It is already allowing people to make 999 calls from areas where it was previously impossible, with almost 400 new masts built so far in some of the most remote areas of Britain.
“When fully implemented, its mobile technology and infrastructure will transform the emergency response of police officers, firefighters and ambulance crews. This will result in faster and better treatment for victims.”
Motorola Solutions, one of the main contractors to the ESN programme, said it is “committed to working with the Home Office to deliver the Emergency Services Network as we move toward delivering the next generation of public safety to the UK”, adding: “We continue to work closely with the Home Office and other partners throughout the incremental roll-out of the programme to ensure a smooth transition for emergency services across the UK.”