Urgent government action is needed to safeguard jobs in the aviation industry and ensure its survival, a cross-party group of MPs has said.
The newly formed Future of Aviation Group issued the call in a letter to Transport Secretary Grant Shapps.
The group of 40 MPs complained of "the lack of progress" in providing wider support for the industry.
And they asked how often the government would review its planned quarantine for new arrivals.
From 8 June, people entering the UK from abroad will be told to isolate for 14 days or face a £1,000 fine.
The quarantine plan has already attracted fierce criticism from the travel industry, with more than 70 travel bosses denouncing it in a separate letter to Home Secretary Priti Patel.
"The very last thing the travel industry needs is a mandatory quarantine imposed on all arriving passengers which will deter foreign visitors from coming here, deter UK visitors from travelling abroad, and most likely cause other countries to impose reciprocal quarantine requirements on British visitors," the travel firms' letter says.
Airlines have been announcing job losses and restructuring programmes as they fight to stay in business. The latest is EasyJet, which said on Thursday that it planned to cut up to 30% of its workforce - about 4,500 jobs.
"The wider aviation family makes a significant economic and social contribution to the UK and will be central to our long-term economic recovery," the MPs wrote to Mr Shapps.
"We are therefore concerned at the lack of progress being made in providing wider support for the industry and in the development of a long-term roadmap that will enable the sector to recover as quickly as possible and play its vital role in our national overall economic recovery."
The MPs called on the government to prioritise "air bridges" to restart safe travel to and from low-risk countries.
"We need urgent action now to safeguard jobs," they added. "The consequences of inaction in this vital area are simply unthinkable."
A Home Office spokesperson said: "As the world begins to emerge from what we hope is the worst of the coronavirus pandemic, we must look to the future and protect the British public by reducing the risk of cases crossing our border.
"We continue to support businesses in the tourism sector through one of the most generous economic packages provided anywhere in the world. However, it is right that we introduce these new measures now to keep the transmission rate down and prevent a devastating second wave."
Do the quarantine rules apply to everybody?
There are a number of groups who are exempt, including:
- Road haulage and freight workers
- Medical officials who are travelling to help fight coronavirus
- Anyone arriving from the Republic of Ireland, the Channel Islands, or the Isle of Man
- Seasonal agricultural workers if they self-isolate on the property where they are working
Initially, it was suggested the rules would also not apply to travellers from France. However, the government later insisted the quarantine measures will also apply to them.
The travel firms say the sector contributed £200bn to the UK economy last year, around 9% of gross domestic product.
But they say the government has been "woefully slow to react and has procrastinated to the point of absurdity" when considering support schemes for the industry during the crisis.
The letter says the government "must not exceed its mandate".
"The people of this country do not wish to be prevented from travelling."
"Quite simply, it is time to switch the emphasis from protection to economic recovery before it is too late."