The Internet Service Providers' Association (ISPA) says it is "extremely disappointed" that the digital economy bill is set to become law.
It has criticised the agreement between the Labour and Conservative front benches to push through the legislation despite "serious concerns" remaining over some of the clauses.
"The decision to accept the government amendment to clause 18, which enables the Secretary of State to make provisions about the granting of blocking injunctions by a court, is unacceptable given the lack of consultation on the impact of the clause," the ISPA stated.
A spokesperson for the association said it was "with much regret" that the majority of parliamentarians had been persuaded by copyright owners to forego parliamentary scrutiny.
As a result, "disproportionate and unworkable" legislation has been forced through, serving only to preserve failing business models, ISPA added.
Broadband provider TalkTalk has also criticised the passage of the bill, vowing to defy the new filesharing laws when they come into force.