Ministers' refusal to publish a report on a giant BAE Systems' arms contract with Saudi Arabia has been branded an "absurdity and a scandal".
BAE Systems continues to be under the spotlight
Liberal Democrat MP John Pugh has launched a bid to give MPs access to the National Audit Office document.
Keeping it secret only succeeded in creating a "miasma of suspicion and allegation", Mr Pugh told MPs.
Tony Blair has said a Serious Fraud Office probe into the deal was dropped for national security reasons.
Mr Pugh, a member of the public accounts committee, said he understood this argument and that it may have put UK jobs at risk.
But he added: "What I cannot accept is that this house has to forfeit the right to examine such a claim."
His Inter-Governmental Contracts (Provision of Information) Bill would seek to "provide a mechanism whereby Parliament's right to at least scrutinise the doings of government can be preserved."
The Bill would apply to commercial contracts involving the government and outside firms.
"I strongly believe that such a mechanism should exist if only so that Parliament is not reduced to the supine, ludicrous position where it is not even allowed to read its own papers simply because the government, in obviously shoddy arguments, tells us it can do us no good," he told MPs.
The NAO, an independent body which scrutinises government spending, compiled its report after examining the original British Aerospace deal, which was signed in the 1980s.
It remains the only report by the organisation never to be put into the public domain, said Mr Pugh.
Urging its publication, Mr Pugh said press coverage of the SFO decision had fuelled suspicion and allegation and "painted a worse picture than ever the dear old National Audit Office could and I believe actually does".
The government's position in keeping the report secret was "unsustainable" and would "only get worse," he said.
"Thanks to their cackhanded approach, no one now believes the Serious Fraud Office were getting nowhere, everyone now believes BAE gave out bribes and the Saudis took them," Mr Pugh told MPs.
"Imagination flourishes in the face of the shiftiness that sits on reports, stops investigation and mistakenly tries to rope in the intelligence service into the whole charade."
The Saudis were now being "demonised,? added Mr Pugh, "our European allies are outraged and the corrupt regimes of the world are smugly vindicated by our apparent, and cynical display, of realpolitics".
Mr Pugh's call comes after fresh evidence of government pressure on the Serious Fraud Office to drop its inquiry into the Saudi deal emerged.
SFO head Robert Wardle was pressed at least seven times to drop his criminal investigation into alleged bribery by the British arms manufacturer before he did, Parliamentary answers obtained by the Lib Dems reveal.
Mr Wardle was pressed three times by the prime minister, three times by the ambassador to Saudi Arabia and once by BAE, which stood to lose a large contract.
BAE has strongly denied setting up a "slush fund" to win the 1980s deal with Saudi Arabia.