Senior police officers have told the Home Office they have lost confidence in its ability to deliver IT projects designed to modernise policing.
In a letter, leaked to the Times, they question why a series of projects have run over budget and been delayed.
It includes a telecommunications network intended for the emergency services, which has cost billions and is three years overdue.
The Home Office said it shared "concerns over delays".
"We are replacing decades-old national police systems to bring powerful new capabilities to policing," an official told BBC news.
"This is already having an impact on the front line, enabling officers to take fingerprint checks in the field and improving the detection of number plates belonging to criminals.
"But we share the concerns over delays.
"And we will continue to work with all our partners to ensure these projects are delivered as efficiently as possible to protect the public."
Other projects mentioned in the letter include:
- a biometrics system intended to speed up fingerprint matching across police forces, which it said was millions of pounds over budget and delayed
- a new data programme to combine criminal records for the police and security agencies
The new Emergency Service Mobile Communications programme, meanwhile, is at least £3bn over budget and three years late.
A National Police Chiefs' Council representative told BBC News: "It's crucial that police have IT systems that enable us to protect the public from harm and tackle crime.
"We continue to work with the Home Office on a number of IT programmes to replace or improve current IT systems."