WHEN it comes to toys, what is all the rage and what is not is the Christmas question parents are racking their brains to answer.

This year the BEN can reveal that a host of classic favourites are set to take the toy shelves by storm -- including the 25-year-old DIY hospital board game Operation.

Pressure on Father Christmas to deliver the correct presents mounts each year.

And, coupled with high demand and shortages of the most sought-after toys, Santa and his helpers appear to be facing another tricky time on December 25.

But fear not. The British Association of Toy Retailers (BATR) has forecast this year's top 10 toys for Christmas -- and there are a few surprises on the list.

Toy chiefs say parents will face difficulties buying anything to do with schoolboy wizard Harry Potter. A Lego version of Harry's school, Hogwarts Castle, retailing in stores at £79.99, has sold on the Internet for £321.

Stores are being sent limited supplies of all merchandise and most retailers have refused to accept advance orders for the castle, the biggest toy in Lego's range of 11, because they cannot guarantee supply.

The situation is similar to that of the Teletubbies, Buzz Lightyear and Thunderbirds Tracey Island toys in previous years.

Most other toys in the top 10 however should prove less troublesome.

Trevor Beaton, general manager at Woolworth's Big W store in Manchester Road, Bolton, said: "We have had phenomenal success in our toy department this year, outstripping our expectations.

"This has been due to some Harry Potter magic and old favourites like Thunderbirds."

Hospital board game Operation, a children's favourite for the past 25 years, is set to make a welcome return this Christmas. And demand for pogo sticks, Action Men, Barbie dolls and a toy candy floss maker is set to soar.

Board games adapted from TV shows including Who Wants to Be a Millionaire? and the Weakest Link will also prove a big hit.

Woolworths say the Megasketcher by Tomy, similar to past favourite Etch-A-Sketch, is also attracting high sales.

BATR spokesmen Moira Downie said: "Pogo sticks are a bit of a surprise package this Christmas but scooters have been doing well all season. They are great fun.

"Mums will be happy with the candy floss machine because it does not make large quantities and the kids will find it great fun. The board game Operation is apparently also doing well again."

Prices for the Christmas favourites range from £8 for Harry Potter figures to Hogwarts Castle at £79.99.

"Drilling" Bob the Builder, the whole range of World Wrestling Federation (WWF) merchandise, Thunderbirds playsets and the Nutcracker Barbie also all feature.

The BATR says a range of Bob the Builder Duplo and an all-crying, all-talking "Baby Annabell" are also all selling well and are expected to enter the Top 10.