The government says it will allow the lease by British Airways of some Qatar Airways planes and crew to help cover a 16-day strike by some UK staff.
Transport Secretary Chris Grayling says BA can lease nine Qatar A320 and 321 planes and crew after advice from the Civil Aviation Authority (CAA).
BA will use the staffed planes to minimise flight cancellations and passenger disruption from Saturday.
The 16-day strike was prompted by what Unite union calls BA’s “poverty pay”.
The long-running industrial action concerns around 2,000 of the airline’s mixed-fleet staff who, if they joined since 2010, fly short and long-haul routes mainly from Heathrow airport and earn less than cabin crew on earlier agreements.
The airline has already cancelled a small number of flights from Heathrow and merged others, but the leasing deal with Qatar means BA will be able to get the vast majority of passengers to their destinations.
A spokeswoman for the carrier said: “We will operate 99.5% of our schedule. Our Oneworld partner, Qatar Airways, will be operating a small number of short-haul flights on our behalf.”
“We have merged a very small number of Heathrow long-haul services and all customers affected have been notified over the past week.”
The airline needed to apply for approval from Mr Grayling and the CAA had to make a recommendation to the minister because the Qatari aircraft and crew are coming in from outside the European Union.
A spokesperson for the UK Civil Aviation Authority said: “An application by British Airways to temporarily ‘wet lease’ [hiring plane and crew] nine Qatar-registered aircraft has today been approved by the UK Department for Transport.”
Unite had requested the CAA recommend blocking the wet-lease deal, claiming it broke EU regulations and cited concerns over Qatar’s human rights and labour standards record.
The union brought about the unprecedented strike action because of a pay dispute and it claimed the airlines had removed concessions and perks for staff if they had taken part in previous strike action.
Unite national officer Oliver Richardson said: “Vindictive threats from British Airways amount to corporate bullying from an airline more interested in punishing workers on poverty pay than addressing why cabin crew have been striking.”