General trade union GMB has rejected the latest pension scheme offer from British Airways (BA).
Paul Kenny, the union's general secretary, believes that members covered by the BA pension scheme are getting a poor deal and he has threatened industrial action.
A showdown over the issue is expected tomorrow between Mr Kenny and BA chief executive Willie Walsh.
Ed Blissett, GMB national negotiator with BA, said: "The members clearly believe that the current pension offer favours the highest paid workers in BA at the expense of the lowest paid.
"GMB members do not want to cause the travelling public any inconvenience and so they have asked their negotiators to try to negotiate a settlement with BA.
"However, GMB cannot rule out the possibility of an industrial action ballot sometime in the future if negotiations are unsuccessful."
The pension rejection comes after the near-miss of a BA strike in January. Walsh was embroiled in discussions with Transport and General Workers Union (T&G) general secretary Tony Woodley to avert strikes called for by cabin crew staff in a dispute over pay and the management of sickness absence.