Labour will try to force the government to release its latest assessment of the impact of Brexit on the economy through a binding Commons vote.
The leaked study suggests that in three different scenarios the UK economy would grow more slowly than it would if it stayed in the European Union.
Shadow Brexit secretary Sir Keir Starmer said MPs needed the details to make informed decisions.
The government said the document could damage UK negotiations with the EU.
The leaked document, titled EU Exit Analysis – Cross Whitehall Briefing, suggests that almost every part of the economy would do less well as otherwise expected, according to Buzzfeed which has seen it.
It looked at scenarios ranging from leaving with no deal to remaining within the EU single market.
Brexit minister Steve Baker said the government would not be publishing the study, adding that it was at a “preliminary” stage and had not been approved by ministers.
It “does not yet take account of the opportunities of leaving the EU”, he said, adding that civil service forecasts were “always wrong, and wrong for good reasons”.
But Labour’s Sir Keir said: “People voted to leave the European Union in part to give Parliament control about its own future.
“That means giving MPs the information they need to scrutinise the government’s approach to Brexit.
“Ministers cannot keep sidelining Parliament to hide the deep divisions within their own party,” he added.
“They should accept this motion and allow the country to have an informed debate about its relationship with Europe after Brexit.”
In an opposition day debate later, Labour will use an archaic parliamentary procedure to bring a vote which would be binding on the government.
On Tuesday, a number of pro-Remain Conservatives joined opposition MPs in calling for the analysis to be released, suggesting the vote could be close.
Former Conservative chancellor Kenneth Clarke accused ministers of trying to protect the government from “political embarrassment” in refusing to release the document.
The report, seen by Buzzfeed, suggests UK economic growth would be 8% lower than current forecasts, in 15 years’ time, if the country left the bloc with no deal and reverted to World Trade Organisation rules.
It says growth would be 5% lower if Britain negotiated a free trade deal and 2% lower even if the UK were to continue to adhere to the rules of the single market.
All scenarios assume a new deal with the US.