From April 1 the helicopter which is based at Shoreham Airport will providing night time medical cover for Sussex, Surrey and Kent until 1.30am.

The current air ambulances for the three counties cannot fly at night but the police helicopter with its night time flying equipment has the capability to be scrambled during the hours of darkness.

The Sussex Air Ambulance Fund will fund the extended service and if successful will upgrade it so a critical care doctor will be added to the night crew crew as well as the current paramedic on board.

David Philpott , Sussex Air Ambulance chief executive said: "We have for sometime been working alongside the police helicopter based at Shoreham in daylight hours with both our helicopters being available in the county and used according to need.

"This new partnership brings us a step closed to being able to offer an enhanced helicopter emergency medical service to the people of Sussex during the hours of darkness as well during the day, which will save even more lives."

Sussex Police Assistant Chief Constable Jeremy Paine said: "As an emergency service we understand too well the difference timely medical help can make to a severely injured person. This collaboration allows us to invest further in our helicopter so it can support future police operations in Sussex as well as providing night time air cover in a medical emergency."

The police helicopter often performs search and rescues alongside the coastguard and attends road traffic collisions to transport casualties quickly to the nearest hospital. In an average year it carries 120 casualties and finds 30 missing people.

The Kent, Surrey and Sussex air ambulances operate a dedicated helicopter emergency medical service from two bases, one at Marden in Kent and the other at Dunsfold Park in Surrey.

They can reach anyway in the three counties from the nearest base in less than 20 minutes. It costs £3million a year to operate the air ambulances across Kent, Surrey and Sussex and is entirely funded by public donations.