A planned directive would allow painters, printers, tapestry makers, ceramists and photographers to claim part of the proceeds of sales of their work - but not glass artists, who have been specifically excluded.
Since the invention of the portable furnace in 1964, artists worldwide have been moulding, pouring, stretching and colouring glass into abstract sculptures, busts, mobiles and murals, as well as ornate jars, jugs and cups.
A glass art movement took root in the US, spreading to Europe, where it was practised with intense avant-garde verve in communist Czechoslovakia. It has been slow to gain recognition in Britain, but is growing in popularity.
Now a dispute has broken out over the proposed Euro-law, which would - in effect - allow artists to claim royalties on their work, if it is sold by a gallery or an auction. An EU document has noted that the European Parliament wanted to include "glass among the original works of art giving rise to resale right", but that this had been "rejected by the commission".
The reason, it says, is that national laws and international agreements on royalties generally exclude glass art, because they are "applied arts," although it does not explain why this has not affected its treatment of ceramics or tapestries.
There are 447 glass artists registered with the UK Crafts Council, and the numbers are growing. Last year a Contemporary Glass Society was formed to represent their interests.
Its chairman Peter Layton said: "I'm appalled. It seems an antiquated way of thinking. We're not frightened of getting politically involved if that is required. It's extremely important to get recognition. For glass, there's not a huge market at the moment, but it will grow. If you are running a glass blowing studio, it's cost intensive. You need enough to live on. This would be a significant help."
The stakes could be high. In the US - where glass art is more established than in Europe - pieces by artists such as Howard Ben Tre and Dale Chihuly can fetch $10,000. In the UK, said Mr Layton, engraved bowls encrusted with gems made by Anna Dickinson and irregular cross and circle sculptures by Colin Reid have fetched pounds 6,000.
The chairman added that the diversity of glass arts would make the commission's ruling unmanageable, with artists such as David Reekie using painted wood, enamel and bamboo cane, as well as glass in their work.
A commission spokeswoman stressed that the proposal had to be discussed once more by the European Parliament, before it could become law, so there was still time to change its contents.
But its view that glass art is an applied science is unlikely to appeal to British engraver Alison Kinnaird - who has said of glass: "It has the intrinsic character of water, light, air and ice. It is a mirror and a window, an elusive and illusory medium - there but not there. It's purity and clarity can give an other worldliness to the images that it holds."
The dispute has come a month ahead of the opening of a pounds 16m National Glass Centre, in Sunderland, which is to exhibit glass art and trace the history of British glass making. This followed the opening in 1994 of a glass gallery in the Victoria and Albert Museum, London, with 6,500 works and the staging of a Glass Show at the Crafts Council Gallery in 1993.
Today, Crafts Council director Tony Ford opposes Brussels' stance, saying: "Some really naff fine art will get protection, while some really good glass art won't be covered." He said the rule would muddy the long running debate over what divides art and craft. The craft of jewellery was a case in point, he said. "It has no obvious function. Most people would call it pure decoration. It's very hard to define."
He also warned that the directive would allow member states to set minimum prices on the art on which artists could claim royalties. These could be high, and so only rich, established artists would benefit.Reuse content