Cross-channel operator Eurostar could be facing further strikes after union bosses decided to ballot members on industrial action.
Saturday's strike caused no disruption, Eurostar said
The Rail, Maritime and Transport (RMT) union said 375 engineers will now vote on whether to launch a campaign of strikes in a dispute over pay.
It comes just days after action by staff at the firm's terminals in Ashford, Kent and London's Waterloo.
Customer service staff staged a 24-hour walk-out over a separate pay row.
A spokesman for Eurostar said the door was "always open" for talks with the RMT to try to resolve the dispute.
"The ball is in the union's court," the firm added.
But the RMT said the vote was as a result of Eurostar failing to resolve outstanding issues from last year's wage settlement - including office hours, facilities and wages.
General secretary Bob Crow claimed that Eurostar management had either "stopped negotiating or failed to make any move at all" to resolve the problems.
"We have made it clear that the union is prepared to talk, but so far we have still heard absolutely nothing from Eurostar," he told the Press Association.
Eurostar said Saturday's strike had little impact, with just seven check-in related staff not turning up for work out of 1,300.
The dispute with check-in staff concerns pay differentials between employees in London and Kent.