Lives are at risk because paramedics cannot see the numbers on people's homes, emergency service chiefs warned today.

Crucial seconds are lost because crews have to drive up and down looking for the right address.

Now Sussex Ambulance Service is backing a major new national campaign called 999 Where Are You?

Thousands of posters outlining the initiative are being sent to hospitals, surgeries, libraries and schools.

Problems are often caused at night when numbers easily visible during daylight hours are obscured.

Sussex Ambulance operations director Trevor Anderson said: "When an ambulance is called, every second counts.

"Finding the house quickly can make the difference between life and death. We are asking the public to make sure that their house number can be seen day or night in the event of an emergency.

"We can't help them until we can find them."

A web site has also been developed to give advice and information on what to do at www.999whereareyou.org.

It often takes just one or two minutes for an ambulance crew to find a house, but that can easily double or treble when confusion comes into play.

Suggested solutions include making numbers or names large enough to be seen, placing them on a wall or gatepost next to the road and keeping foliage cut back.

Shops and businesses are also being encouraged to make their signs and numbers easier to spot.

Sussex Police back the scheme. Assistant Chief Constable Nigel Yeo said: "I wholeheartedly support the campaign by the ambulance service, which is also relevant to the police.

"My officers regularly lose valuable time locating addresses because they are not clearly marked.

"The extra time it takes to find a house can not only make a difference between life and death, it can also make a difference in crime prevention."