As one of the UK's biggest internet service providers with over 4 million subscribers, TalkTalk has long opposed the government's approach to fighting online copyright piracy.
Writing on the TalkTalk blog, the firm's director of strategy and regulation Andrew Heaney criticised the "oppressive" digital economy bill, particularly its requirement for ISPs to block the connections of targeted persistent offenders.
On Wednesday, the bill was voted through parliament after culture secretary Ben Bradshaw amended and dropped certain clauses.
New powers to block websites suspected of hosting illicit material were watered down, but controversial measures to prevent file-sharing remained intact.
In response, Heaney warned that the approach will place greater onus on home networks to protect themselves from hackers at a "collective cost of hundreds of millions of pounds a year".
Last October, the firm staged a wireless stunt to show just how easy it is to hack into home networks and begin illegally downloading material.
Heaney claimed that the government's anti-piracy stance is based on the presumption that people are "guilty unless they can prove themselves innocent".
He also said that the website blocking measures could still wrongly stop legitimate search engines and websites, such as Wikileaks, from operating.
"This is made all the more appalling by the ability of big music and film companies to influence government and the absence of any proper debate or scrutiny by MPs - only 5% of MPs turned up for the brief debate [on Wednesday] and the other important parliamentary stages will be bypassed in the 'wash-up' process," he said.
"TalkTalk will continue to battle against these oppressive proposals - they will require 'secondary legislation' before they can be implemented. After the election we will resume highlighting the substantial dangers inherent in the proposals and that the hoped for benefits in legitimate sales will not materialise as file sharers will simply switch to other undetectable methods to get content for free."
Heaney pledged that TalkTalk will only enact a disconnection notice or surrender a customer's details to rights holders if it is "served with a court order".
He added: "We are the only major ISP to have taken this stance and we will maintain it. If we are instructed to disconnect an account due to alleged copyright infringement we will refuse to do so and tell the rights holders we'll see them in court."
As the bill passed through parliament, six Labour MPs rebelled against the measures, including former Cabinet Office minister Tom Watson, who went against the whip for the first time in his nine-year career as an MP.
Open Rights Group executive director Jim Killock also strongly criticised the anti-piracy stance, arguing that it will discourage public venues from offering wireless internet access.
"This is an attack on everyone's right to communicate, work and gain an education. Politicians have shown themselves to be incompetent and completely out of touch with an entire generation's values," he said.
"There are thousands of activists working with ORG planning to show up at hustings, demand answers from candidates, and who are willing to punish those who voted for this at the ballot box."