John and Yoko joined in bed by Chris Evans

JOHN LENNON is to make his television advertising debut, 18 years after his murder in New York. The former Beatle will appear in a plug for mobile phones. Lennon's posthumous appearance, to be shown next week, may sound like bad taste, but it is part of a trend.

Dead celebrities can command big bucks, as advertisers are discovering, and the latest digital technology is enabling them to cash in as never before. In the One2One ad, DJ Chris Evans is taken back to Lennon's famous peace protest in Amsterdam when he spent a week in bed with Yoko Ono.

In the US, dead people are particularly sought after to promote products. One licensing agent recently acquired the commercial exploitation rights to Marilyn Monroe at auction, for $7m (pounds 4.3m) - a year.

Previous One2One ads have featured deceased celebrities including Elvis Presley and Martin Luther King.

Blending old and new footage is nothing new. But new technology means dead personalities can now interact seamlessly with or even endorse products developed long after their death and it is raising calls for limits on how far advertisers should be allowed to go.

Research to be published this week shows that 90 per cent of the public want the law changed to force advertisers to obtain permission from surviving family members.

In the US advertisers eager to use a dead celebrity must first secure a licence from those managing the estate - but there is no such requirement in the UK.