91Èȱ¬

The then shadow minister for the Cabinet Office Nick Hurd said the Tories could not support the census in its current form, and it should be scaled back to save money and reduce its impact.

He was reacting to plans that mean everyone in England and Wales will have to reveal who slept in their home on the night of March 27 2011, their qualifications and marital status, and what type of central heating they have, on pain of £1,000 fine.

So, how have things changed since the coalition took over from Labour, and Mr Hurd became a minister in the Cabinet Office?

The director of the England and Wales census Glen Watson told the 91Èȱ¬: "They haven't expressed those reservations to me since taking office." His plans have not changed since election day.

Cabinet Office minister Francis Maude said: "The expenses already committed to the census mean any changes are difficult.

"However we are looking at ways to reduce the cost and will examine the best models to carry out this function in the future".

Separate, but similar census operations are being run in Scotland and Northern Ireland on the same day as the exercise in England and Wales.

As Conservative ministers accept that making changes to census plans at this stage will be problematic, the first hints of a campaign against filling in the forms is emerging.

Alex Deane from the Big Brother Watch campaign group is encouraging anyone who finds the questions intrusive not to comply.

He said: "I don't imagine for a moment that putting a blank or palpably absurd answer - Mickey Mouse, Donald Duck - would result in a prosecution for anyone, and anyone who feels that they're having their privacy intruded upon should feel free in my view to put that."

Data collected by the census is used to allocate £100bn of central government money to council and health authorities.

Personal information will not be released for a century. Those who do not fill in forms could be fined £1,000. Offering nonsense answers is also an offence.

But protesters have long realised they can use the exercise to make a political point. In 1911 the suffragettes boycotted the census.

In 2001 390,000 people in England and Wales sought official recognition for the faith of Luke Skywalker by listing their faith as 'Jedi'.

None of the suffragettes were punished for rebelling against the census. Before next year's work the authorities will be keen to remind people of the fine. Afterwards they will have to decide who to punish.

Mr Watson revealed that in 2001 3m people did not return a completed census questionnaire. Fewer than 100 were prosecuted.

He said: "We have to have made contact. So quite a lot of the people that don't return the questionnaire, our census field staff have not been able to make any contact and you cannot prosecute a house."

Despite the threat of prosecution, the census authorities and the government will be relying on their powers of persuasion to achieve mass acceptance.

That means Conservative ministers will need to convince the public to embrace a census of which they have been so critical.