Les Mis has been a global success

Union members are unhappy with plans to replace part of the orchestra when Les Miserables moves to a smaller venue.

Both sides have said they want to reach an agreement following reports that musicians were prepared to strike.

But Sir Cameron has warned that the show could close early if an agreement was not reached.

The two sides have agreed to meet again to discuss possible ways to avoid cutting Les Miserables' orchestra by 12 when it moves from the Palace Theatre to the Queens Theatre.

"We are waiting to see what they come back with," the union's spokesman told BBC News Online.

"We are still hopeful, but we will all lose out if the proposals go ahead," he added.

The producer wants to use a Sinfonia, a machine which replicates instruments, to replace the missing musicians.

'No dispute'

Sir Cameron Mackintosh and his production company have stated that there is "no dispute" with the Musicians' Union.

If they fail to find a solution, the West End could suffer its first industrial action in living memory.

Sir Cameron said: "If a satisfactory arrangement cannot be made with the Musicians' Union then this could result in the premature closure of this highly successful production."

The composer of Les Miserables has given his support to Sir Cameron.

Claude-Michel Schonberg said: "At theatres in London where the number of musicians is limited by the size of the pit, we want to use the maximum amount of live musicians that can be accommodated, combined with technology, to ensure the highest standards."

"Any fan of West End musicals will recognise that the orchestra is the beating heart of the production," said Horace Trurbridge, assistant general secretary of the Musicians Union.

"Take the musicians away and you remove at a stroke one of the vital elements of the live theatre experience," he added.

Highest standards

Union general secretary John Smith said: "Our members are very concerned about the impact this may have upon the ability to attract theatregoers from home and abroad."

Claude-Michel Schonberg, composer of Les Miserables, said the number of musicians that can be used in West End orchestra pits is "limited".

"We want to use the maximum amount of live musicians that can be accommodated, combined with technology to ensure the highest standards," he added.