British Airways has recently introduced charges for pre-booking seats
British Airways has said it is to cut 1,700 jobs and plans to introduce a two-year pay freeze for cabin crew as it looks to cut costs in the downturn.
The airline also announced it would press ahead with plans to recruit new staff on different terms and conditions to current employees.
The airline is losing money and expects to make a big loss for the second consecutive year.
Global airlines are struggling with a fall in passenger numbers.
"Revenues are down, so we must reduce costs and restore profitability," BA said.
From Wednesday, British Airways passengers will have to pay a fee of up to £60 to choose their seats more than 24 hours before take-off
"Thousands of staff across the airline have already made contributions to the cost reduction programme."
The airline said the job cuts would involve 1,000 cabin crew taking voluntary redundancy and a further 3,000 choosing to go part-time, and would take effect from the end of November.
"Without changes, we will continue to lose more money with every month that passes. It is essential we make ourselves more efficient if we are to ensure our long-term survival," BA said.
The Unite union criticised the cuts and warned BA staff in an email that "you can rest assured it won't be the last [job cuts]."
The airline has been in negotiations with unions about the best way to cut staff costs.
This summer, it asked employees to volunteer to work for free for one month, to take unpaid leave or to work part-time.
It has also scrapped sandwiches on short-haul flights and is introducing charges on pre-booked seats.
In the year to the end of March, BA made a loss of £401m - its biggest loss since it was privatised in 1987.
Earlier this month, the International Air Transport Association (Iata) increased its forecast for losses across the whole industry to $11bn (£6.9bn).