The prime minister has been sent a video message from 38,000 musicians calling for an extension to copyright protection.
Under current rules performers' copyright runs out after 50 years though for composers and authors it extends for 70 years after their death.
And the musicians' group has urged Gordon Brown to back a European Commission directive to extend the copyright protection to 95 years after release.
The video features 29 musicians - who have worked with the likes of the Beatles, Frank Sinatra and Madonna - calling for the government to support the extension.
"British session musicians are the finest in the world, the absolute finest," said Derek Wadsworth, who has recorded with the Rolling Stones and Tom Jones, among others.
"The amount of revenue that's been brought into this country by these people is quite staggering. Now we require the government to help us out a little bit and show perhaps a bit of gratitude."
He added: "Instead they choose to kick us in the face and ignore our campaign to extend the copyright for these people and their estate."
Phil Pickett, a former session musician for Culture Club, said changing the copyright rules would mean a small but significant boost to musicians' incomes.
"Ninety per cent of musicians earn less than £15,000 a year. These royalties are very small but they add up over the years," he told the BBC.
The video message to Mr Brown comes as the European Commission commences a debate on the European Copyright Term Directive.
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