(TheAustralian) - WINE industry veteran Wolf Blass has attacked supermarket majors Coles and Woolworths for slashing returns for winemakers and called for an industry-wide levy to promote Australian wine overseas. "The biggest risk in the domestic market is the catastrophic duopoly controlling 60 per cent of our market," said Mr Blass, whose eponymous brand is now owned by Treasury Wine Estates. "It is a situation where there is no profit to be made, and if there is no profit there is no money for development." Mr Blass, who now works as a brand ambassador for TWE, promoting the Wolf Blass label at home and abroad, said the company needed to do more to support independent retailers and restaurants to help maintain a profitable market for its own products in the face of cut-throat discounting by the supermarket majors.