British Airways' passengers who thought they might avoid disruption that will be caused by forthcoming strikes now face potential chaos on both sides of the Atlantic.
It has been revealed that BA cabin crew union Unite has been in talks with US-based union the Teamsters - part of the International Transport Workers Federation (ITF) - about joining industrial action at the US airports where its members work.
Unite announced on Friday (March 12) that its members would walkout for three days from March 20, and for four days from March 27.
The airline responded by insisting that up to 60% of customers would be unaffected, as a number of contingency plans would fall into place.
Some 1,000 BA staff from across the business had been retrained as temporary cabin crew, meaning most long haul flights to North America would have evaded cancellations.
But the Teamsters union commands some 40,000 members in the aviation sector, and it is feared that ground handlers and airport services workers will act to disrupt any BA services.
According to the BBC, officials form Unite and the ITF are due to meet again today (Wednesday, March 17).
The move is likely to further galvanise international trade union support for the cabin crew struggle. Messages of support have already been received from Germany, France and Spain.
A spokesman from Teamsters said: "We stand in solidarity with our brothers and sisters at Unite who are fighting for a fair contract at British Airways.
"ITF affiliates around the world are mobilising to support British Airways workers in their fight for passenger safety and worker respect."
BA said it was "sad" that Unite had decided to internationalise the dispute in its attempts to "bring down the company".
"It is sad to see Unite seeking backing from trade unions overseas to support its unjustified strike against an iconic British brand."
Politicians have become embroiled in the issue in the last week since both the Transport Minister Lord Adonis and prime minister Gordon Brown branded the strike "totally unacceptable".
Their outbursts were seen as a political gamble, given the unite Union is the Labour Party's largest donor.
Labour's deputy leader Harriet Harman, whose husband Jack Dromey is deputy general secretary of Unite, said: "I accept the strike is deplorable. It is not right to put at risk those who have planned holidays and those working at BA."
Conservative transport spokeswoman Theresa Villiers damned the union, accusing them of deliberately seeking to cause maximum disruption.
"Unite should not be striking at all and trying to spread the dispute to other countries is even more irresponsible," she said in a statement.
Meanwhile, BA has agreed a new deal with unions to alleviate the £3.7 billion funding gap in its two final salary pension schemes.
Staff enrolled in the schemes will now pay a larger percentage - up to an additional 4.5% - of their salary towards the scheme.