A small present could make a big difference to Harrow's sick children this winter so the Observer is calling on all readers to support its annual Christmas Toy Appeal.

Our festive campaign, which has the backing of pop stars Scouting for Girls plus the Mayor of Harrow John Nickolay, is running for its fourth consecutive year to put a smile on the faces of poorly children in the borough.

But we can only do this with your help. The Observer would like to build on the extraordinary generosity our readers have shown in the past and ask them to buy an extra gift this Christmas to give to a child at Northwick Park Hospital.

On December 11 presents will be delivered to the hospital in Watford Road, Harrow, by indie rock band Scouting For Girls who grew up in and around the borough and have topped the UK album charts this year.

The remainding gifts will find their way to deserving families via Harrow Council's social services department.

To kick start this year's appeal Mr Nickolay visited children at the hospital yesterday (Wednesday) where he chatted with youngsters.

He said: "Children are so important, they are our future and it is unfortunate that some will have to spend Christmas in hospital.

"It must be very frightening for some of the little ones. "By donating a present you will make a child feel very special this Christmas."

Last year Harrow singer-songwriter Kate Nash cheered up youngsters at Northwick Park Hospital where she was born by presenting gifts which included signed copies of her CDs. Other celebrities who have supported our campaign include TV presenter Fearne Cotton and actress Anna Popplewell, who starred in the 2004 movie The Chronicles of Narnia.

Sarah McKellar, head of communications for The North West London's Hospitals NHS Trust, welcomed the toy appeal and said the hospital was proud to be involved again. She said: "We were overwhelmed with the generosity of Observer readers last year. The gifts make such a difference to children who have to be in hospital over the festive season and help to bring some cheer at what can be a very tough time for them and their families. We are delighted that the appeal is happening again this year."

Observer editor, David Tilley, is urging readers to support the campaign. He said: "Christmas is a busy and expensive time of year but by adding just one extra gift to your list you will be making a sick child from the borough very happy."