BT believes the Digital Economy Act will be overturned in a judicial review because it breaches Europen legislation.
Last week, BT and TalkTalk revealed they were calling for a judicial review into the controversial Act, which covers a number of issues including measures designed to tackle internet piracy, because they believed it had been "rushed through" earlier this year, to ensure it became law before Parliament was dissolved in preparation for the General Election that was held in May this year.
"It cannot be held that the Digital Economy Act got a fair ride in Parliament," Simon Milner, director of group industry policy for BT, said at an e-Forum on file-sharing.
"The House of Commons barely got a look at this. Both houses should have a proper look at something, especially if it's controversial."
Milner said he believed the government did not follow due process in terms of EU law.
"It simply did not have the time, because it tried to rush it through. In our view, the court will decide that it's not fine."
However, Thomas Dillon, a former general counsel for the Motion Picture Association, claimed the arguing over the Act was undermining the law.
"It's a done deal. It's too late for that."
Dillon also said he believes ISPs should exercise their contractual right to cut off or suspend someone who's a convicted file-sharer, rather than take a softer approach outlined by Ofcom in a Code of Practice earlier this year.