London – British Airways was scrambling Saturday to deal with the start of a three-day strike by its cabin crew that has thrown the plans of thousands of travelers into chaos.

BA chartered planes from rival airlines, drafted in volunteer crew from among its other work force and rebooked some passengers on other services in a bid to keep as many passengers happy as possible.

Chief Executive Willie Walsh issued a direct apology to passengers via YouTube, saying it was a "terrible day for BA."

The Eurostar train service between London and continental Europe and Virgin's rail services between London and Scotland were expected to be busy as passengers sought alternate routes.

The Unite union has gathered some support from unions in the United States, Germany and Spain for its action, but they have so far stopped short of pledges for coordinated activity that would disrupt BA's ability to refuel and service the planes it is operating over the walkout.

As protesters were readying picket lines Saturday outside London's Heathrow international airport, analysts estimated that BA has already lost more than 25 million pounds (more than $37 million) because of canceled tickets and contingency costs.

Aside from hurting BA, the strike is also an unwelcome event for Britain's governing Labour Party before national elections expected before June.

Prime Minister Gordon Brown irritated Unite, a major political donor, by calling the union "deplorable," and as late as Friday evening was urging it to call off the strike.

Britain was facing more possible travel chaos in the run-up to the Easter break, as railway signal workers voted last week to join rail maintenance workers in a strike. The Rail Maritime and Transport union has not called dates for the walkout, but refused to rule out the long Easter weekend on April 2-5.

And over this weekend, engineering works on the London Underground were forcing closures between central London and Heathrow, though the Heathrow Express train service was operating as normal.

"As the country struggles out of the recession, the last thing we need is the unions holding the country to ransom," said Theresa Villiers, the opposition Conservative Party's transport spokeswoman.