Aslef members who drive Eurotunnel's shuttle trains voted by 110 votes to seven to ban overtime, it was announced yesterday, in protest against the company's refusal to negotiate pay and conditions with the union.
Instead, Eurotunnel - which has hitherto been the only train operator not to recognise unions - signed a single union deal in June with the Transport and General Workers' Union to represent all staff, under pressure from the new union recognition legislation.
The dispute has come to a head at the peak period for cross-Channel traffic - last year nearly 1m cars and more than 200,000 lorries were carried on the shuttle during the summer.
Eurotunnel's managing director Bill Dix said yesterday he was confident the industrial action would have little or no impact, because overtime on the shuttle service was "extremely limited" - less than 1% between January and June this year.
But an Aslef spokesman said the union would hold a full-scale strike ballot if the company failed to respond and added that the union was also determined to improve Eurotunnel drivers' pay, which at an average of £18,000 a year was the lowest in the country.
"Eurotunnel should talk to Aslef before their industrial intransigence inconveniences the public," said the union's general secretary Mick Rix.