Former Statistics Canada chief Munir Sheikh was set to tell agency staffers the National Household Survey "will not provide useful data" to groups that use the mandatory long-form census, but the meeting was cancelled and he resigned hours after the government was made aware of his proposed comments, newly released documents reveal.

"Many of you have asked whether I believe the National Household Survey will satisfy the needs of all users of the previous long form," reads a draft of a speech Sheikh was to give at a staff town hall meeting on July 21.

"My response is that the NHS will meet the needs of many users but will not provide useful data to meet the needs of other users of the mandatory long-form census data."

The draft of Sheikh's speech is contained in nearly 200 pages of emails and briefing notes released by the government Tuesday to the House of Commons Industry committee. The government distributed the documents to reporters before they were made available to committee members.

The committee is probing the government's decision to scrap the mandatory long-form census and replace it with the voluntary National Household Survey.

The move has been widely criticized and experts say the data will be virtually useless because some groups will be less likely to respond to a voluntary survey.

According to the documents, the draft of Sheikh's speech was emailed to the Privy Council Office (PCO) and Industry Canada early on the morning of July 21. Hours later, the town hall meeting was cancelled and Sheikh resigned from his post.

"This relates to the question of whether a voluntary survey can become a substitute for a mandatory census," Sheikh wrote in a statement announcing his resignation. "It can not."

Many of the documents released Tuesday are blacked out and several are undated, making it impossible to establish a detailed picture of the discussions between the agency and the government.

But a series of emails on July 16 between Sheikh, Industry Minister Tony Clement's office and the PCO show the government tried to control StatsCan's message on the issue.

The PCO asked Sheikh to use the phrase "StatsCan is confident that the National Household Survey will meet the needs of a broad range of users" when making public comments about the change.

Sheikh said he preferred to say that "a census by its design is able to meet a broader range of data demands than a survey. The National Household Survey will meet the needs of many users."

Clement's office then suggested deleting the reference to the design of a census.

The new documents prove a claim Sheikh made to the Commons committee last month that he quit his job over reports the agency recommended scrapping the mandatory census. Sheikh said those reports, which were based on statements by Clement, were damaging to the agency's credibility.

Clement backtracked from his claims during his testimony before the committee, saying it was the government's decision to scrap the mandatory long-form census and that the agency did not agree with the move.

As of 2011, Canadians will no longer be required to complete the long-form census, which 20 per cent of the population normally had to fill out. Replacing that is a volunteer survey sent out to 33 per cent of homes.

The switch from the mandatory long-form census to a voluntary survey will cost the federal organization about $30 million. About $5 million will be spent to mail out the survey to 60 per cent more households and up to $25 million to encourage public participation.

With files from The Canadian Press