Householders take the least care with the back door with 1.3 million people leaving it unlocked even though police figures show one-in-four successful burglaries involve criminals gaining access via an unlocked door.

In a poll of 1,168 adults, some of the reasons given for not locking-up were: a belief neighbours were keeping an eye out - 18 percent, a belief the area had a low crime rate - 18 percent and just plain forgetfulness - 10 percent.

''With street crime rising by 8 percent this year, the idea that any street in Britain is safe enough for you to leave your door unlocked is little more than a nostalgic notion,'' said Vicky Emmott, senior underwriter at Halifax Home Insurance.

''But judging by the findings of our report, millions of Britons still live in the past,'' she said in a statement.

She said the best advice was the simplest -- lock external doors even when at home.