A report by the Commons Transport Select Committee accused the airline of a “calculated attempt to take advantage” of the crisis by cutting up to 12,000 jobs and downgrading the terms and conditions of the bulk of its remaining employees.
The carrier insisted it is doing everything it can to “sustain the maximum number of jobs”.
Other aviation companies have also announced thousands of redundancies, including easyJet, Ryanair, Virgin Atlantic, Rolls-Royce and Airbus.
The cross-party committee of MPs acknowledged that job losses in the sector “may sadly be inevitable” due to the huge reduction in air travel as a result of Covid-19.
But it urged UK-based employers not to “proceed hastily” by making large numbers of people redundant while the Government’s furlough scheme is in place.
Unions told the committee that British Airways is operating a “fire and rehire” approach by giving redundancy notices to most of its 42,000 workers with the intention of offering jobs to a proportion of them under worse terms and conditions.
This is in addition to up to 12,000 job losses.
The minimum 45-day consultation period for some workers ends on Monday.
BA has had discussions with pilots’ union Balpa, including over the possibility of voluntary redundancies.
But the other two main unions representing its workers – Unite and GMB – are not engaging in talks.
The committee found that British Airways had received nearly £35m from the Government as of May 14 by furloughing 22,000 staff.
It noted that at the end of 2019, the carrier recorded profits after tax of £1.1bn and cash reserves of £2.6bn.
Unions have argued that the airline could survive even if all its planes were grounded for 12 months.
The committee’s report stated: “The behaviour of British Airways and its parent company towards its employees is a national disgrace.
“It falls well below the standards we would expect from any employer, especially in light of the scale of taxpayer subsidy, at this time of national crisis.”
The sentiment was echoed by Don Valley MP Nick Fletcher, who does not sit on the committee, but said: “Myself and many of my Parliamentary colleagues have been horrified that BA is using this Pandemic to restructure its firm; by carrying out many redundancies and forcing through what it tried to achieve in 2010. I'm afraid that this is not right.”
He said he was disappointed the airlines chief executive had initially not attended a roundtable discussion with the Home Secretary and Aviation Minister.
And he suggested that “favouritism based on national lines is taking place right in front of our eyes” as IAG, the Spanish firm which owns British Airways, was not laying off staff in Spain.
He said: “I can only hope that British Airways will come to its senses and stop these heartless and unnecessary layoffs.
“As it currently stands, therefore, one of the world’s iconic brands is sacking 12,000 employees and revising all of its existing employees' contracts at a time when there is uncertainty for everyone.
“Doing this to your employees when they are at rock bottom emotionally and financially is hardly what you would call a good PR exercise.”
He added: “I am in no doubt that following this pandemic, we will see British Airways planes fly again. Yet if BA is not going to change course, both the consumers and their employees will lose out significantly.”
There have been calls from some MPs for British Airways to be stripped of some of its lucrative take-off and landing slots at Heathrow as punishment for the treatment of its workforce.
Tory MP Huw Merriman, who chairs the Transport Committee, said: “We will continue to bring pressure where we can, including the airport slot allocation process.
“This wanton destruction of a loyal workforce cannot appear to go without sanction by Government, parliamentarians or paying passengers who may choose differently in future. We view it as a national disgrace.”
British Airways said in a statement: “We find ourselves in the deepest crisis ever faced by the airline industry. A crisis not of our making but one which we must address.
“We will do everything in our power to ensure that British Airways can survive and sustain the maximum number of jobs consistent with the new reality of a changed airline industry in a severely weakened global economy.”
Unite general secretary Len McCluskey said: “The case the company makes for sacking 12,000 and trashing the wages of those who stay on the workforce is full of holes because it is a transparent effort to generate profits out of a crisis.
“BA is fooling nobody. Never before has the country witnessed such wholesale mistreatment of a UK workforce and such brutal industrial thuggery.”
The committee’s report into the impact of the pandemic on the aviation sector urged the Government to abandon its 14-day quarantine rule at the end of June.
It called for a “more targeted and nuanced border control policy”, allowing people travelling from countries where the infection rate of Covid-19 is relatively low to enter the UK on a less restrictive basis.
The report also recommended that the Government and devolved administrations – where they have not already done so – provide support aimed specifically at the aviation sector, including a 12-month business rates relief for airlines and airports, and a six-month suspension of air passenger duty payments.
A Government spokesman said: “We continue to work at speed to help protect the long-term future of the sector, however we will always put public health first, and we must not risk an extremely damaging second wave of the virus.”