A non-emergency telephone number for around-the-clock access to NHS services is to be rolled out nationally.
The 111 line, which has been trialled in a small number of areas, will dispense advice but also organise care as appropriate from GPs, community nurses or an ambulance.
It is billed by the Tories as reducing confusion and effectively abolishing the concept of "out-of-hours" in the NHS.
The line, which will replace that provided by NHS Direct, is to be made available nationally by April 2013.
After pilots in County Durham, Nottingham, Lincolnshire and Luton, it will be extended to the Isle of Wight and Chesterfield before Christmas.
According to the NHS Direct is expected to "retain a role" in the delivery of the 111 service, which will be staffed by call advisers supported by nurses.
Health Secretary Andrew Lansley said: "The new 111 service will mean patients can access the whole of the NHS through just one simple number. This marks another important step in modernising the NHS and giving patients greater control and choice over their healthcare."
Dr Clare Gerada, chairwoman of the Royal College of General Practitioners, said: "Not only will callers to the service be advised on what to do but also to be directed to the appropriate local service to address their need consistently. However, patients should be aware that this is not a replacement for the current system and that they can continue to call their GP practice as normal."
Prime Minister David Cameron said: "I believe people should get the care they need, when and where they need it. However, too many people are confused about what is available to them or how best to get it, especially at night or if they are away from home.
"That's why we are introducing NHS 111. The new service will make sure callers can access the care and advice that is right for them, 24 hours a day, 365 days a year."
