UK cable broadband and TV provider Virgin Media has made a formal complaint to Ofcom, urging the communications watchdog to investigate Project Canvas.
In a 74-page document submitted to Ofcom yesterday, Virgin argues that the BBC-led TV venture is anti-competitive.
Project Canvas is a partnership between broadcasters the BBC, Channel 4 and ITV, along with communications providers BT, Arqiva and Talk Talk, to build an open, internet-connected set-top box TV platform.
In a statement, Virgin said: "The Canvas partners have significantly exceeded their original claims to be creating a common set of open standards which could have been improved upon by others and are now intent on controlling every aspect of how people watch TV."
The Office of Fair Trading ruled in May that it couldn't investigate Canvas because the partnership was not a formal merger, and so fell outside monopoly rules.
Virgin complains that even after the recent departure of partner Channel 5 from the project, the broadcasters involved in Canvas still account for 75 per cent of all UK TV viewing, while ISPs BT and TalkTalk between them share more than 50 per cent of the broadband market.
The BBC Trust recently approved the public service broadcaster's participation in the £130 million project, but Virgin now argues that the tight constraints placed on elements such as Canvas's electronic programme guide, and the stipulation that it cannot be bundled with other products or services, mean that commercial partnerships with the project are difficult.
Other broadcasters, including BSkyB, have considered lodging a complaint about the open TV platform.