So I continued using my nasty plastic brush until today when I came across the Preserve toothbrush in our local Sainsburys. This brush is made from recycled plastic including yogurt cups from a nearby supplier. It comes with a reusable travel case with ventilation holes. When it's time to replace it you can send the brush and its case back to Preserve to be recycled into plastic lumber for picnic tables, boardwalks and decks. And it only cost £1.99 (although I seem to remember it being on special offer at the moment).
To be fair Mrs A did mention the Preserve brush in her blog but was put off it by the need to ship it back to the States for recycling. Well she need worry no longer because the bush and case can now be returned to an address in Haverhill.
I bought two brushes for the girls for their trip to France. I shall be buying another for myself as soon as my current brush is too worn out to be any longer effective