The recommendation, made to the UK Statistics Authority, comes following a programme of research, which began immediately after completion of the fieldwork for 2011’s census, and a three-month public consultation. Two methods were put forward for consultation: an online census and a combined method using administrative data supplemented by sample surveys.

In the 2011 census, households were sent paper forms, with online entry available as an alternative. This resulted in 16% of completed forms being submitted online, according to ONS. The recommended online approach would result in online being the priority mode, with other modes available for the ‘unconnected’ population.

The alternative administrative data solution would make use of existing sources such as the NHS Patient Register and the DWP/HMRC Customer Information System to produce annual population estimates, which would then be adjusted for biases by supplementing with annual coverage surveys of 1% of the population.

In an overview of the two methods, chair of the MRS Census & Geodemographics Group Barry Leventhal concluded that the online census appeared the better option for both richness of output and cost of provision. He added that administrative data could improve annual population estimates and could be implemented alongside an online census. Responding to today’s recommendation, Leventhal said: “My immediate reaction is that I’m delighted with the recommended ‘direction of travel’ that’s been announced for collecting census-type data in the future, and I’m sure that it’s the right approach to be putting forward.

“If Government agrees with the recommendation, as I hope they will, and are prepared to support the long-term development of administrative data solutions in parallel with an online census in 2021, then this is a real opportunity for improving our data for the future.”

CEO of the Market Research Society Jane Frost, said: “While the decision to move the Census to a predominantly online format is consistent with technological developments it is not without its risks. One of the benefits of the Census is that it provides solid evidential data to identify ‘hidden groups’ in society, but these groups won’t necessarily have access to technology. The ONS also needs to ensure that the correct data protection and security measures are implemented to prevent data hacking or leaks.”

SIr Andrew Dilnot, chair of the UK Statistics Authority, who wrote to Minister for the Cabinet Office Francis Maude to make the recommendation, said: “I am very grateful to colleagues in ONS for all their hard work over the last three years to complete a thorough and extensive review of the future provision of population statistics in England and Wales and the options for the next census.

“Along with the Board of the Authority, I welcome the National Statistician’s recommendation and commend it to the Government and Parliament.”