Leading figures from Scotland's whisky industry are asking drinks giant Diageo to rethink the marketing of its Cardhu malt.
Cardhu is now made from a mixture of whiskies
Senior directors from Scotland's 16 other main distillers met to discuss the controversial decision to change the composition of the famous brand.
They have now agreed to write to Diageo and the Scotch Whisky Association over the issue.
"Their key message is that the industry cannot compromise on the protection of single malt Scotch whisky," said a spokesman for the group.
"To this end Diageo should reconsider the use of the name Cardhu - which has been the name of a single malt Scotch whisky for the last 30 years - as a mixture or vatting of malt whiskies.
"We are confident that sense will prevail."
Cardhu is now being made from a mixture of malt whiskies from several distilleries on Speyside.
Other distillers are angry that Diageo is continuing to use the name Cardhu while only changing the word "single" to "pure" on the label.
Some have accused the company of misleading the public, cheapening malt whisky as a brand and damaging the industry's reputation.
Ian Meakins, Diageo's president for Europe and supply, said: "We are pleased that the companies represented at yesterday's meeting have agreed to continue to work through the SWA to resolve the current debate.
"As previously stated, we have at all times sought to resolve the issue with the rest of the industry through the Scotch Whisky Association.
"We remain committed to the long-term future of the SWA as the best forum for continuing this debate and seeking to develop a common and coherent voice for Scotch whisky."
The Scotch Whisky Association is due to hold its next meeting on 4 December.