The sat-nav system that many motorists rely on could start to fail next year, the US government has warned.
A report from the Government Accountability Office (GAO) claims that there has been mismanagement and under-investment in America’s satellite system by the US Air Force.
Officials now say the 20-year-old global positioning system is in urgent need of upgrading to stop it crumbling.
The system, known as Navstar GPS, is already £562 million over budget and delays have further hampered its development, said the US Government Accountability Office.
The first replacement satellite is not due until November, but was expected two years ago. The lack of investment means that both military and civilian systems could be affected.
"It is uncertain whether the Air Force will be able to acquire new satellites in time to maintain current GPS service without interruption," the GAO warned