The leader of UK union Bectu has accused Ofcom of " treachery" over its sale of the UK's spectrum.

Tony Lennon, president of Bectu, called for a public value test to decide on the best use of what was a valuable resource.

"I am stunned that public property is being packaged up and sold off in this way," he told the BBC. "If Ofcom gets it wrong it will be a massive act of treachery."

Ofcom has yet to decide on the process for the 2009 auction, which will sell the airwaves freed up by the 2010 to 2012 switch off of terrestrial broadcasting.

Lennon maintained that the process could not be decided based on the wishes of those expected to spend huge amounts in the auction.

"Effectively what Ofcom is doing is selling it off to the highest bidder," he said. "Allowing the people with the biggest cheque books to decide is not the best way and, as well as economic tests, each bid should be assessed on social criteria."

Bectu has around 27,000 members in the UK covering audio-visual and entertainment areas such as broadcasting, film, and interactive media.