Ministers are to be urged to strengthen Freedom of Information laws and extend them to charities, private companies and the Royal household.
Liberal Democrat MP Tom Brake is to table a proposed law change which would prevent ministers from overruling decisions by the Information Commissioner and Information Tribunal.
His plans would also stop the House of Commons Speaker from vetoing FoI requests without a public interest test being applied.
It comes after John Bercow invoked a controversial loophole in the FoI Act to withhold material, in response to a request by the Press Association, thought to raise concerns about the extent of drinking in Westminster's subsidised bars.
Brake also wants a limit on how much time public authorities can take when deciding whether the release of information is in the public interest.
His extension of the existing laws would result in social enterprises, charities and private companies contracted to carry out work for public authorities being subject to FoI legislation, along with the Royal household, which provides support and advice to the Queen.
Former minister Brake has insisted FoI laws are "fundamental to our democracy".
His proposals emerge as a Government commission, the members of which include Labour former home secretary Jack Straw and ex-Conservative leader Lord Howard of Lympne, reviews the scope of existing legislation.
Campaigners fear the commission will seek to impose fees or reduce access while the Information Commissioner Christopher Graham has cautioned against a return to the "dark ages".
The Society of Editors, backed by Press Gazette and Holdthefrontpage, launched the Hands Off FoI campaign in response to the commission. And a related Press Gazette petition, calling on the Government not to weaken the act, has been signed by more than 42,000 people.
Labour leader Jeremy Corbyn is also opposed to the introduction of charges for FoI requests, telling a Westminster lunch earlier this month that he would be "absolutely against" such a move and that freedom of information was "essential in any democracy".
Cabinet minister Chris Grayling has previously accused journalists of "misusing" the laws to "generate" stories.
Brake, who will put forward his plans in the House of Commons tomorrow, told Press Association: "FoI is fundamental to our democracy and that is particularly true at a point where the Government unfortunately do not have any opposition."
Asked if he was referring to the state of Labour, he said: "Yes, then we are very short in numbers and the SNP focuses pretty much on Scotland.
"It's people like you who can use FoI to hold the Government to account who should not be constrained. Attempts to restrict FoI are what I will fight against.
"I have always been very perplexed at Tony Blair's statement that the worst thing he did was introduce FoI legislation. I thought it was going to war in Iraq."
Brake's Freedom of Information (Public Interest and Transparency) plan is unlikely to become law if it fails to receive Government support or sufficient parliamentary time.