Iron Maiden frontman Bruce Dickinson, broadcaster Sir Trevor McDonald and actress Helen Baxendale have urged companies to sponsor one of the phone lines run by a missing people's charity.

Missing People, which works to find and safeguard missing people and support their loved ones, wants firms to show their support by sponsoring a phone for £10,000. It has 12 lines available for sponsorship.

The event was hosted by vice-patron Sir Trevor McDonald, at the charity's headquarters in South-west London and was attended by the charity's corporate and celebrity supporters and ambassadors.

Sir Trevor McDonald said: "I am delighted to formally launch Missing People's Sponsor A Phone Campaign.

"Each of these phones really is a life-saving piece of equipment, providing support to some of society's most vulnerable people.

"By sponsoring a Missing People phone for £10,000, companies and individuals can help to ensure that vulnerable people can access crucial support 24 hours a day every day in 2010."

Guest of honour was Kerry Grist, the mother of Ben Needham who disappeared more than 20 years ago from the Greek island of Kos.

Kerry said: "Without the charity Missing People, there are families like mine across the country who simply would have nowhere to turn. To me they are a godsend."

During the evening tributes were also paid to Stephen Gately who died on Saturday. Stephen had been an ambassador for Missing People for more than four years, calling the helpline services "a vital resource".

Martin Houghton-Brown, chief executive at Missing People, said: "Missing People has launched the Sponsor A Phone Campaign to offer individuals and companies a unique opportunity to provide a life-saving piece of equipment.

"Missing People's helplines are the conduits through which our staff and volunteers help runaway children and young people into a place of safety, or set up a three way call which could reunite a broken family. Via this sponsorship we can ensure that we answer every desperate cry for help in 2010."

Missing People provides support for missing children, vulnerable adults and families left in limbo. We offer families of the missing specialist advice and practical support as well as searching and securing publicity.

To make a donation to Missing People call freefone 0800 2987858 or visit www.missingpeople.org.uk/donate.

To find out more about the Sponsor A Phone Campaign visit www.missingpeople.org.uk/sponsoraphone or call 020 8392 4510.