Brexit minister Steve Baker says it will take “no more than three weeks” to publish official reports on the impact of Brexit on Britain’s economy.
The government had been ordered to publish the reports immediately by Commons speaker John Bercow.
But Mr Baker said officials needed more time to “collate” the information.
He was accused of a “cover up” and of being in contempt of Parliament by opposition MPs and some on his own side.
He rejected these claims, saying time was needed to “bring together this information in a way that is accessible”.
And he questioned the motives of Labour MPs calling for immediate publication, asking them: “Whose side are they on?”
He accused Labour of pursuing anti-Brexit stories and insisted the 58 studies did not include “qualitative” analysis of the impact of Brexit on the economy as they were expecting.
Labour’s Pat McFadden said the minister’s questioning of MPs’ patriotism “cannot stand” and demanded the studies be handed over to the Commons Brexit committee in un-redacted form straight away.
Committee chairman Hillary Benn said the un-censored documents should be released to him without delay and it “should be for the committee to decide in what form they are published”.
Conservative MP Anna Soubry – who campaigns against Brexit – accused Mr Baker of “gross contempt” of Parliament by not publishing the documents.
Lib Dem MP Tom Brake, who originally requested the documents through a Freedom of Information request, accused the minister of mounting a “cover-up”.
Eurosceptic Tory MP Peter Bone also added his voice to those calling for the immediate publication.
But the minister was backed by several Conservative MPs, including the Brexit committee’s deputy chairman, John Whittingdale, who said he accepted Mr Baker’s reasons for the delay.
The government had originally sought to keep the 58 studies secret, saying they would undermine Brexit talks.
They were effectively forced into agreeing to their publication by a Labour motion last week in the Commons.
Labour MP Matthew Pennycook, who raised the issue by asking the urgent question in the Commons, said: “This farce has dragged on for far too long. There can be no further delay – and ministers just need to get on with it.”
Mr Baker told him: “We will provide this information to the (Brexit) committee as soon as possible. We currently expect this to be in no more than three weeks.”