Actress Joanna Lumley has been joined by Dover MP Gwyn Prosser to protest against the return of live calf exports from Britain to mainland Europe.
Joanna Lumley and Gwyn Prosser protested in Whitehall
Trade resumes on Wednesday following a 10-year ban on cattle exports imposed in the wake of BSE.
The Absolutely Fabulous star presented a petition and a giant postcard to Agriculture Minister Ben Bradshaw.
She campaigns for Compassion in World Farming (CIWF), which successfully lobbied against the use of veal crates.
The crates were banned in the UK in 1990, but CIWF said that exported calves still faced the same conditions on the continent, where crates remain in use.
Ms Lumley said exported calves also faced a "horrific" journey.
"Our message is don't start this vile export again," she said on Tuesday.
The National Farmers' Union (NFU) said new EU regulations coming into force in January 2007 would outlaw the use of veal crates.
It said it was asking potential calf exporters to give written assurances that calves from Britain would only be exported to rearing units that comply with the new regulations.
"The resumption of the export trade in live calves, whilst very welcome from a farming point of view, is bound to be controversial," it said.
"It is essential that it is conducted with the maximum transparency and to the highest possible standards."