British Airways said it expected to fly 75% of its customers today (March 29) and tomorrow - the last two days of the current cabin crew strike.
The airline said it had been able to expand its flight schedule "because of increased numbers of cabin crew wishing to work as normal".
But Unite, the employees' union, disputed the figures, claiming that "more than 50% of those rostered to work are on strike".
It said BA's figures were "another distortion" as they did not include those who were not rostered to work over the four-day stoppage but were on strike.
The strike, the second this month, was called after talks between the two sides on changes in working conditions broke down.
BA said its flights out of London Gatwick and London City airports along with services run by its subsidiary, franchise, alliance and codeshare partners were operating normally.
It said it would fly more than 180,000 of the 240,000 people booked to travel with the airline during the strike.
The carrier said a further 18% had been re-booked with other airlines or changed their travel dates.
Willie Walsh, BA's ceo, said he was "delighted that we will be able to fly such a large proportion of our customers to their chosen destinations in the coming days.
He added: "The vast majority of British Airways staff, including thousands of cabin crew, are pulling together to serve our customers and keep our flag flying.
"At the same time, I feel really sorry for those customers whose plans have been ruined by Unite's completely unjustified action.
"Despite the union's promises, this strike has affected the Easter holiday plans of thousands of hard-working people."
In a statement issued yesterday afternoon, Unite said that on a normal day, BA had 2,100 cabin crew on duty.
BA had cut the number of staff reporting for duty and only 359 staff had signed into work since the strike started last Saturday.
"That leaves BA with 259 crew at work today," Unite said.
Unite also rejected the claim by David Cameron, leader of the UK opposition Conservative Party, that the union had encouraged its members to strike because it "scented weakness" by prime minister Gordon Brown on the dispute.
A union official said the remark demonstrated Cameron's naivety on industrial relations.
Brown told a British television programme yesterday that he wanted the cabin crew back at work, and that he was doing all he could to end the dispute.
www.ba.com www.unitetheunion.com