A small number of Heathrow flights will be "merged", but BA said all flights to and from Gatwick and London City airports will operate as normal.
The strike planned for Christmas Day and Boxing Day was subsequently suspended, before a new 48-hour strike was announced after cabin crew rejected a new offer aimed at resolving the dispute.
Unite said over 800 cabin crew from British Airways' so-called "mixed fleet" had joined the union since the start of the dispute, taking its membership to over 2,900.
What is the BA cabin crew strike action all about?
The row is about the pay received by the 'Mixed Fleet' cabin crew who have joined the company since 2010;
Unite says earnings for its members were advertised between £21,000 and £25,000 but in reality started at just over £12,000 plus £3 an hour flying pay;
A Unite survey found half of its Mixed Fleet members have taken on second jobs to make ends meet, and 84% said they had experienced stress and depression since joining BA due to financial circumstances;
Meanwhile cabin crew are angry that British Airways and the parent company IAG reported profits of €1.4 billion - up 64% on last year - while boss Willie Walsh pocketed €8.8 million.
Unite's National officer Oliver Richardson said: "More and more 'mixed fleet' cabin crew have joined Unite as this dispute over poverty pay has gone on.
"Increasingly tired of delivering a first class service for poverty pay, 'mixed fleet' cabin crew are at breaking point over pay levels which are forcing many of them to take a second job or turn up to work unfit to fly.
"Despite British Airways walking away from meaningful talks we would urge it to listen to its 'mixed fleet' cabin crew who work tirelessly to serve passengers and contribute massively to the success of the airline.
"With the parent company of British Airways forecasting annual profits in the region of £2.3 billion, it's clear that the UK's national carrier can pay the people who keep us safe while we fly a decent wage."
Timeline of BA cabin crew strike dispute
14 December: Unite announces that thousands of BA cabin crew had voted overwhelmingly in favour of strikes, threatening disruption to flights over the Christmas period.
16 December: BA announces cabin crew will strike on Christmas Day and Boxing Day.
19 December: Talks aimed at averting strike action get underway at Acas.
22 December: Unite says the strikes planned for Christmas Day and Boxing Day have been suspended.
3 January: Unite says BA cabin crew are to stage a 48-hour strike from January 10 after its members rejected an offer aimed at resolving the dispute by 7-1.
6 January: BA reassures customers they will be able to fly to their destinations during the planned strike.
10 January: 48-hour strike gets underway
BA said: "As part of our contingency plan, we will be merging a very small number of flights to and from Heathrow.
"This will mean some customers will travel slightly earlier or later in the day than their original booking.
"We look forward to welcoming more than 200,000 customers on to our flights across the two days and ensuring they can all proceed with their holiday breaks, visits to friends and family or business meetings."