Chief executive Alex Cruz said the coronavirus pandemic has “devastated our business” and the carrier is “still fighting for our own survival”.
He told the Commons’ Transport Select Committee: “Fewer passengers means fewer flights, and fewer flights means fewer people required to actually service them.
“As CEO of British Airways, I have to take responsibility. I cannot ignore the situation. I had to act incredibly fast."
He added: “I deeply, deeply regret that way too many loyal and hardworking colleagues of mine are having to leave our business, and I understand why MPs are concerned.”
In April, British Airways announced plans to cut up to 12,000 jobs, representing nearly 30% of its workforce.
Mr Cruz said: “This is an impossible situation. We’re having to make incredibly difficult decisions as a consequence of this pandemic and it is really only because of Covid-19 that we have had to go through such deep restructuring.
“I have to make these difficult decisions at this time but I am completely dedicated and focused on protecting those nearly 30,000 jobs of those British Airways colleagues that will remain within the business.
“People are still afraid of travelling.
“Of course, we are having weekly changes, as you know, to the quarantine list. We don’t have a testing solution yet. And still our customers are paying APD (air passenger duty) even just to fly on domestic regional flights.
“So the overall situation is quite challenging, and this is why we are taking every measure possible to make sure that we can actually make it through this winter.”
Mr Cruz told the committee British Airways held “very difficult and yet very constructive” meetings with pilots’ union Balpa, which resulted in a package being agreed on job and pay cuts aimed at avoiding a larger number of redundancies.
But non-pilot unions “chose different paths and decided not to engage with us”, the chief executive added.
He said the airline sent the unions “over 500 pages of proposals, ideas, potential mitigations” and invited them to more than 520 meetings which they did not attend.
But an agreement has been reached with the non-pilot unions – such as those representing cabin crew – and staff are being balloted.
Trade union Unite had accused the airline of planning a “fire and rehire” scheme involving remaining employees having their terms and conditions downgraded.
Mr Cruz said: “We have reached agreements, in principle, which will mean that there will be no need whatsoever to issue new contracts.
“It will just be using the standard methodology of the union agreement which makes some amendments to the existing contracts, and we hope that the majority of that process will finish this week.”