Households which have not yet completed and returned their census forms face being visited by officials from the Office for National Statistics.

Some 7m homes will be visited by around 29,000 census collectors, who will help, or persuade, people to complete the compulsory form.

Pete Benton, Deputy Census Director from the Office for National Statistics, said the cost of sending out collectors and the £1,000 fine for those who do not fill in the forms reflects "just how important the information is".