Mothercare sell them....look like fabric but have a waterproof backing. Saw some really great ones in Tchibo for £3.99 but I doubt they still sell them as they never sell anything for long. Also think Asda have them which will probably be the cheapest.
I was thinking the other day that I would probably have been better to buy some painting aprons from elc or similar. Then they are completley plastic and can be wiped down. We had to get lots of the fabric ones (with plastic backing) because they get so caked with food after each meal and are constantly in the wash. We also still use a rubber over bib with moat to catch the worst.
Hiya, These coverall bibs are fab. I had some from toysrus & some from Mothercare & found the Toysrus ones the best - the elasticated cuffs were much better quality so food didn't end up down the armholes! BTW, don't put them in the tumble dryer like my dh did......it melts the plastic Iona xx