Without knowing who has created the works, people can bid for them on eBay until the auction, called The Big Art Secret, closes on Sunday. Proceeds from the sale will go to St Wilfrid's Hospice. Hockney's work is "an ink and colour crayon drawing on a postcard" and Emin has donated four postcards.
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Amanda Houston has the lunchtime forecast for the west of the ITV Meridian Meridian region.
Amanda Houston has the lunchtime forecast for the east of the region.
The latest weather forecast for the west of the region from Amanda Houston.