Pilots union Balpa has said the UK’s aviation sector faces falling into a "death spiral" of retrenchment and job cuts.
The union has written to chancellor Rishi Sunak demanding a moratorium on tens of thousands of proposed job losses in aviation.
It has also urged the government to redouble its efforts to map out an exit from the coronavirus crisis "that meets the needs of the UK economy".
Prime minister Boris Johnson last week said the government would this week reveal the next steps in its coronavirus "roadmap" and how it would jump start various parts of the economy, including the travel and tourism sector.
Ministers, though, have not yet delivered a much-vaunted support package for aviation, the suggestion of which dates to Sunak’s very first emergency funding announcement in mid-March to limit the impact of the crisis on the economy.
The union says airlines are "deliberately exploiting" the situation to push through job cuts and make changes to working conditions.
"Balpa is calling for government to put a strategic plan in place to ensure UK aviation can survive Covid-19," said the union late on Monday (4 May).
General secretary Brian Strutton added: "UK aviation is facing a death spiral of retrenchment and cuts. Balpa will not stand by and watch the industry crumble or allow airlines to use this as a chance to make unfair redundancies or make unnecessary reductions to terms and conditions.
"The government needs to step in now not only with a package of support, but also to put a proper aviation plan in place, agreed by all stakeholders, to avoid opportunistic attacks on terms and conditions. In the meantime, there should be no knee-jerk decisions and a moratorium on any job losses."