Several leading broadband providers are reportedly seeking to challenge BT's plan to deliver universal high-speed broadband across the UK.
Ministers have promised to implement a new broadband Universal Service Obligation (USO) that ensures everyone in Britain has a legal right to request minimum speeds of 10Mbps by 2020.
According to the government, this is the speed that will meet the typical needs of a family that wants to browse the web, stream films and carry out video conferencing at the same time.
However, BT has volunteered to deliver universal high-speed broadband to all areas of the UK, as an alternative to regulation.
Under BT's offer, which would be primarily delivered by Openreach, many premises would receive speeds substantially faster than 10Mbps. As a result, the proposal could render the planned USO unnecessary.
While no final decision will be made following a consultation on the proposed USO, the Times reports that Sky Broadband, TalkTalk and Hyperoptic would be willing to challenge the plan if it is approved by ministers.
An unnamed source told the newspaper: "The law is very clear on how a USO should be delivered.
"BT and government can’t simply call the USO something else and hope the law doesn’t apply."
The source added that if BT persuades the government to ignore the legal framework, it could face "years in court", which would "derail the process and leave customers waiting even longer for the fast broadband they deserve".
BT's offer has also been criticised by Gigaclear, which said it strongly believes that a regulated USO is "the only way to guarantee a competitive marketplace".
Speaking to ISPreview.co.uk, Chief Executive Matthew Hare commented: "Competition is vital, not only to give consumers choice and access to high quality broadband, but also to secure the future of this country’s digital economy.
"If the government were to go with BT’s voluntary deal, this would effectively stifle competition."