The T&G trade union has accused Scottish & Newcastle (S&N) of reneging on an assurance to its workforce by selling off its pubs, restaurants and budget hotels.
The union says that in mid-April S&N told employee representatives on its European Works Council, a statutory body, that it would not be selling off its pub estate.
But at the end of April S&N announced it had decided to sell after all.
The S&N portfolio consists of 1,450 pubs, restaurants and budget hotels, including the Premier Lodge and Chef & Brewer chains.
T&G national organiser Brian Revell has now written an angry letter to S&N chairman Brian Stewart.
He says: "A couple of weeks ago at a meeting of the European Works Council, an assurance was given that the company would not be disposing of its pub estate. It makes a mockery of the European Works Council when ten days later the company announces their intention to sell off all their pubs and restaurants.
"Clearly the European Works Council has been mislead and I feel its value undermined."
But a spokeswoman for S&N said the decision to sell the pubs was only taken at a board meeting on 24 April, and therefore the company could not have informed the Works Council meeting.
The union wants the council reconvened so the sell-off can be discussed.