Speaking at the retailer's recent tasting, Howard said that while it had seen a sales rise of 35 per cent over the past year, quality needed to improve so it could compete with similarly priced wines from other countries.
Waitrose holds 25 per cent of the market share for English wine and has added a further 15 lines to its range this year, bringing the total to 30.
He said: "We do some fantastically good sparkling wines, but perhaps we don't get the same value for money with English table wine which people sell for £7.99 or £8.99.
"However, compared with a £20 Champagne, English sparkling wine can match it price for price and quality for quality." Three English sparkling wines from Ridgeview and Nyetimber are being included in Waitrose's Summer Fizz Showcase.
The supermarket will be offering promotions on Champagne and sparkling wine from June 4 to July 3.
Speaking at English Wine Producers' recent tasting, Chapel Down sales director Guy Tresnan said: "Three or four years ago price was an issue, but now people - patriots, epicures, those wanting to source wine locally and 'wine grazers' - will pay a premium for English wines." Threshers is planning to list a selection.