Owen Paterson told Sky News that he was against government involvement in regulating the media.
Lord Justice Leveson will be publish his report on Thursday (November 29) following a wide-ranging investigation that heard testimony from media owners, journalists, celebrities and politicians.
The big question over Leveson's inquiry, which was set up after the phone hacking scandal at the News of the World, is what form of regulation it will recommend for the media going forward.
But despite the shocking revelations in the hacking scandal and its fallout, Paterson said that he is fully behind a free press.
"As far as I'm concerned, any government interference in the way the press is run would be a horrible slippery slope," he told Sky News.
"Some dreadful things have happened, some really shocking things have happened. I'm not a lawyer but as far as I can see they were nearly all illegal and due process should have taken place and there should have been prosecutions for what were then illegal acts and remain today illegal acts.
Paterson's comments come ahead of a letter being published, signed by 40 Tory MPs and calling for tougher self-regulation of the press, rather than any kind of statutory system.
In an interview with his local newspaper the Shropshire Star, Cabinet minister Paterson urged the government to "leave well alone" in relation to press regulation.
He said that he could not think of "anything that would discredit politicians more" than to introduce a system of state regulation.
Pressure is building on prime minister David Cameron, who commissioned the Leveson inquiry last year, over how he handles the findings.
Campaigners and some Labour and Liberal Democrat figures have called for state involvement, but Cameron would risk alienating the press and some members of his own party if he backs that route.
Downing Street has said that the prime minster is keeping all options open until the report is released, although some reports have said that full state regulation of the media has already been ruled out.