Never mind the quality, look at the size of it. That is the early verdict on the astronomically large 1993 harvest in Champagne, a haul that should help to keep prices stable, but may prevent the year going down as a vintage one.

The big issue in the streets of Reims and Epernay, however, has not been the harvest nor the judicial sideshows - in which Thorncroft Vineyard and Yves St Laurent have been taken to task for using the name 'champagne', the former for its elderflower perry, the latter for its perfume. No, the big issue has been how to preserve the virtue of the champagne name when it seems in danger of being compromised by an onslaught of inferior fizz from within its own ranks.

The chief culprit remains cheap, industrial champagne, which until recently was available on French supermarket shelves for as little as Fr48 ( pounds 5.65). Cut-price champagnes can be sold cheaply because they are the tail-end of inferior grape pressings, aged for no more than the legal minimum. They may not match the quality or consistency of the grandes marques such as Bollinger or Krug, but they offer the glamour of champagne at a knockdown price. In the first six months of the year, at the expense of the grandes marques, these cheap champagnes increased sales by nearly 50 per cent.

Poor sales have already meant lay-

offs at Moet et Chandon, Mumm, Pommery and Taittinger, and profits pared uncomfortably close to the bone. No wonder champagnes such as Piper Heidsieck and Lanson - both pounds 13.50 about 18 months ago at Auchan, the French hypermarket chain - find themselves down to about the pounds 10 mark. But the more far-sighted producers realise that cutting prices can be only a short-term ploy.

Belatedly, the Champenois in general and the grandes marques in particu1ar are doing something to undermine the idea they created: that the name champagne stands for top quality. Using the 1991 charter of ethics and quality drawn up by Bollinger, the grandes marques are trying to broadcast the message that a better bottle of champagne really is worth the extra that it costs.

Despite misgivings, it is clear the plan is not just a cosmetic exercise. The 28-strong Syndicat des Grandes Marques is submitting itself to the most radical upheaval in its history - 'a cultural revolution', according to one leading champagne producer.

In will come rules requiring a greater proportion of champagne to come from the area's best vineyards (the grands and premiers crus, which comprise only one-third of its 30,500 hectares); more reserve (ie, mature) wines in non-vintage blends; and, more importantly, a longer minimum period of bottle-ageing, a quality criterion that some leading houses would like to see set at three years.

Out will go all but the first (and best) pressing of the grapes; the unethical practice of buying sur lattes ready-made champagnes which have a house label slapped on them; and any of the grandes marques that fail to meet the new criteria.

Observers predict the formation of a leaner and fitter group of 18 or 20 houses by the spring, with the big corporations throwing victims - such as Mercier, Canard-Duchene and Heidsieck Monopole - to the lions. Lanson, too, may depart.

At recent tastings, a good number of the grandes marques emerged smelling of roses. Consistently among the front runners were Bollinger, which melts in the mouth; Billecart Salmon, the most elegant of youthful champagnes with an attractive degree of toastiness; and Charles Heidsieck Brut Reserve, another full-flavoured mouthful, with some reserve wines adding richness. The fine aperitif champagnes - Laurent Perrier, Pommery, Veuve Clicquot, Ruinart, Pol Roger, Louis Roederer, Gosset and, inevitably, Krug - also delivered the goods.

Unfortunately, for every genuinely classy grande marque there are still many that do not justify the high price which comes with the glossy packaging and prestigious name. Among them are not only Mercier, Canard-Duchene and Heidsieck Monopole; Moet & Chandon, too, practically a byword for champagne in the public mind, is unexciting at present.

It would be easy to ignore some of the good value, albeit less illustrious, champagnes - including those from growers, co-operatives and less well- known merchant houses. Without the financial burden of supporting a great brand name, such champagnes often offer excellent value, even if the quality does require careful monitoring. The label of a non-vintage product, grande marque or not, does not at present tell the buyer when a champagne has switched to its new vintage (though astute consumers may be able to decipher it from the code on the neck label).

I have recently mentioned Waitrose Blanc de Noirs, Sainsbury's Extra Dry and Thresher's Jean de Praisac. Also on good form are Safeway's yeasty, fresh Albert Etienne Brut and its richer, deeper 1988 Vintage counterpart. Pierre Vaudon 1er cru is a consistent favourite, while Victoria Wine's perfectly proportioned, full-flavoured 1986 Vintage Champagne and the Wine Society's magnificently mature and toasty 1985 Alfred Gratien are real Christmas treats.

Among growers' champagnes of especially good quality and value, I would single out Albert Beerens, the brilliantly fresh and fruity Chartogne- Taillet, the savoury Royer Blanc de Blancs and Michel Arnould Grand Cru Reserve. And if you happen to be crossing the Channel, a bottle or two of the excellent Champagne Vilmart from Martin Brown's Grape Shop in Boulogne should help to smooth the journey home.

Grandes Marques: Bollinger, pounds 21.49 at Sainsbury's, Fullers; pounds 21.59 at Asda; pounds 21.75 at Waitrose, Tesco, Oddbins (also pounds 17.95 per bottle in a case) and Majestic ( pounds 18.49 per bottle/case); pounds 21.95 at Wine Rack ( pounds 18.82 per bottle for seven). Billecart Salmon, pounds 16.99 at Oddbins ( pounds 14.56 per bottle for seven). Charles Heidsieck Brut Reserve, pounds 19.49, Tesco. Pommery (special offer), pounds 12.49 per bottle for six at Lay & Wheeler, Colchester (0206 764446); pounds 13.99 at Bibendum, London NW1.

Growers, co-ops and other houses: Albert Etienne Brut, pounds 9.95, and 1988 Vintage, pounds 14.99, Safeway. Pierre Vaudon 1er cru, pounds 12.28 per bottle in a case, Haynes Hanson & Clark, London SW6 (071-736 7878). Victoria Wine 1986 Vintage, pounds 15.59. 1985 Alfred Gratien, pounds 19.50, The Wine Society. Albert Beerens, pounds 11.99 offer, Bibendum, London NW1 (071- 722 5577). Chartogne-Taillet, pounds 13.99, Safeway. Royer Blanc de Blancs, pounds 12.99, Oddbins ( pounds 11.15 per bottle for seven). Michel Arnould Grand Cru Reserve, pounds 13.99, Tesco. Vilmart, Fr100 ( pounds 11.35), The Grape Shop, 85-87 rue Victor Hugo, Boulogne (010 33 21 33 92 30).