Christopher Timothy claims 'EastEnders' stars are treated as the BBC's "property".
The 78-year-old star - who is best known for his role as James Herriot in 70s comedy-drama 'All Creatures Great and Small' - admits the "heavy" filming schedule is "quite hard work", and says it is "tricky" to do other projects while contracted to the BBC One soap.
Christopher - who plays Ted Murray in the soap - is quoted by the Daily Star newspaper as saying: "It is quite hard work. It's a heavy schedule and it takes precedence over everything.
"You sign a contract and you are arguably their property until such time.
"To do other jobs at the same time is tricky."
But 'EastEnders' stars are allowed to appear in other projects "with the producer's blessing".
A source told the publication: "'EastEnders' stars can discuss having time away from the show to do other projects with the producer's blessing."
Several 'EastEnders' stars have appeared on 'Strictly Come Dancing' while contracted to the show.
Tameka Empson - who plays Kim Fox-Hubbard - strutted her stuff on the dancefloor in 2016 alongside pro dancer Gorka Marquez, but they were the second couple to leave the show.
One year earlier, Kellie Bright (Linda Carter) appeared on the 13th series of the programme and she and pro partner Kevin Clifton finished as joint runners-up alongside former 'Coronation Street' star Georgia May Foote and Giovanni Pernice, while singer Jay McGuiness clinched the Glitterball Trophy with his partner Aliona Vilani.
What's more, Jake Wood (Max Branning) has been on a break from the soap to tour with his boxing podcast 'Pound for Pound', which he hosts alongside former pro boxer Spencer Oliver.
Speaking last September, an 'EastEnders' spokesperson told BANG Showbiz: "Jake will take some time off early next year, but he will return to filming after a short time away."
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