Thanks. Tried ebay earlier and will have a look at Phenol plywood.
Google found this stuff which looks interesting if it's not too expensive and actually available..
http://uber-eng.com.sg/products_tuffply_intro.htmTuffPly is an engineered plastic composite board / plastic plywood, made specifically for form concrete shuttering faces.
Its very tough & scratch resistant surface suits the rough handling on site and can be nailed, screwed & sawn easily like how you would use a wood product.