The unauthorised appropriation of UK television content by an internet start-up has again left broadcasters angry and frustrated as the debate around digital rights protection moves to live TV.

Zattoo, a young Swiss and US-based company, is on Monday launching a service that allows users to view live television from all of the UK’s terrestrial broadcasters on their personal computers – in spite of having no formal contracts with the BBC, ITV, Channel 4 or Five – thanks to what it claims is a loophole in UK copyright law.