Passengers affected by the British Airways cabin crew strikes should "sit tight" for the next 24 hours, a travel organisation said today.
Frances Tuke, of Abta, said people would be entitled to refunds if their flights were cancelled.
But she said it was possible strike action could still be averted as negotiations took place between unions and British Airways (BA) bosses.
"At this stage, our advice would be to sit tight and see what happens in the next 24 hours," said Ms Tuke.
"It looks as if both sides are continuing to negotiate and we're still hoping it might be called off."
She said passengers would be entitled to either a refund or an alternative flight option under "denied bookings regulations".
But it was unlikely passengers would receive additional compensation, she said.
People who booked directly with BA should contact the firm to get a refund or a change to their flight times.
Those who have booked package holidays should contact their tour operators to ask for their money back or to book different flights, said Ms Tuke.
Although the time frame of the strikes has been announced, Ms Tuke said travel firms were still awaiting confirmation from BA about which flights would be affected.
"We are waiting for a schedule from BA because there are staff that are not unionised and there is a potential pool of workers that could be used to operate flights," she said.
The strike will start on 22 December and will run to 2 January, with hundreds of flights set to be grounded.
Bob Atkinson, of travelsupermarket.com, said bookings made before 2 November "should" be covered by travel insurance.
But he added: "Flights booked on November 2 or after will almost certainly not be covered by your insurance, as the union had announced a strike ballot on that day, therefore people knew action might be on the cards."