The Scottish Government faces a struggle to meet its own key targets for the census despite delaying the deadline.
Everyone in Scotland was originally told to complete the survey by May 1.
The cut-off date was extended by four weeks last month due to dismal uptake.
The SNP Government had already pushed back the census by a year because of the Covid pandemic – despite the Tories going ahead with it in England.
Nicola Sturgeon’s party were earlier criticised by Conservative rivals for not continuing with the UK-wide census in 2021.
The National Records of Scotland target for returned surveys is 94%. Each council area requires a completion rate of at least 85%.
Only Aberdeenshire and the Western Isles have been able to hit the 90% mark with just days remaining.
Dundee has a return rate of 80.8%, better than only Glasgow, Inverclyde and West Dunbartonshire.
It means the Scottish Government are well behind their key targets as rivals branded the process a “shambles”.
Tory MSP Donald Cameron said: “The continued low response rate shows that their rejection of being part of a UK-wide census was completely misguided.
“They put their nationalist ideology above being part of a successful campaign across the UK despite repeated calls from the Scottish Conservatives to carry out the Scottish census in 2021.”
Labour MSP Sarah Boyack said: “The public need answers regarding the shambles of this year’s vital census.
“Millions of taxpayers cash has been spent on this bungled census and yet we are no clearer what exactly has gone wrong. It looks like Scotland might not even reach a 90% completion rate.”
It was revealed earlier this month that census staff had visited more than one million households to try and improve uptake.
Fewer than 80% of households across the country had completed the form when the deadline was first extended.
Why do I have to fill in the census?
Filling out the census is compulsory and Scots who fail to do it on time risk a £1,000 fine.
The survey asks a range of questions on housing, age, sex and job status.
It is regularly used by government agencies and public bodies to help decide where funding should be issued.
The Scottish Government needs to be open.
– Willie Rennie MSP
Ex-Scottish Lib Dem chief Willie Rennie said: “The census is being completed at a snail’s pace.
“The Scottish Government needs to be open about why progress continues to be slow and what more it will now do to resolve this headache.”
SNP minister Angus Robertson insisted it was “vital” to see a higher return rate and pleaded with residents to fill out their forms.
He said: “I would urge everyone who has not completed their census to do so immediately and before the end of May, to avoid the risk of prosecution.”