The unlikely pair met at 11 Downing Street to urge the public to help the thousands of children in Britain and abroad suffering from abuse, illness or poverty.
The unique Appeal First Cheque 2,000 aims to get people to write their first cheque of the next century for 2,000 pence - pounds 20 - to benefit 100,000 children desperately in need of help.
Jerry Hall, who is involved in many children's charities, met youngsters from Brooklands Rise School, north London and the North London Performing Arts Centre on the steps of the Chancellor's residence to help publicise the campaign.
The Texan mother of four of Rolling Stone Mick Jagger's children joked with the Chancellor as he signed his own cheque for the appeal and said: "First Cheque 2,000 is a great way for all of us to start the new Millennium in a meaningful way - your firstcheque will go towards helping 100,000 children."
Braving the freezing November morning wrapped in a magenta coat, Ms Hall looked relaxed in the company of the children and said: "This is a wonderful charity because everyone can make a difference through this appeal and it is so important to helpchildren who need our help.
"I have four children and I feel so sorry for the children who are ill and abused or in war-torn countries.
"We grown-ups who are strong really should do what we can to help them."
Jerry is among a host of famous names who are backing the Millennium appeal, including pop stars Lolly, also at the launch, Phil Collins and Louise Nurding, actresses Dame Diana Rigg and Dame Judy Dench, former hostage Terry Waite, Jamie Redknapp andKevin Keegan from the world of football.
Mr Brown said: "I am honoured to have been asked to launch such a worthwhile appeal.
"Children are our future and it is only right that we help to guarantee them all a bright future in the new millennium.
"As we all enjoy the forthcoming celebrations, I hope everyone in the UK will remember the less fortunate children that First Cheque 2,000 helps and will send off a cheque of their own."
The appeal is being organised by five of the UK's leading children's charities: Kidscape, National Meningitis Trust, Norwood Ravenswood, One-To-One Children's Fund and Starlight Children's Foundation. It was the brainchild of David Altschuler, Co-Director of One-To- One Children's Fund, who said he would like to see it become an annual event.
"Instead of writing your first cheque to pay any old bill, make a real meaningful contribution and make it out to charity instead," he said.
Members of the public will be able to donate money by sending cheques to Freepost First Cheque 2,000, London, or by making a credit card donation on 0870-789-6000.
The launch will be followed by a celebrity shopping evening at Hamleys Toy Shop in Regent Street, central London on December 8 when all proceeds will go towards the appeal. Caption: Hall together now: Mr Gordon Brown joins Jerry Hall and youngsupporters outside 11 Downing Street, to launch the appeal.
© Birmingham Post, by Rebecca Allison