Harsh new lockdowns have triggered a new cycle of cancellations, with the ‘test to release’ scheme “on the backburner” and the government poised to announce new entry restrictions.

International arrivals will need proof of a negative pre-departure Covid test to enter the UK, with Boris Johnson confirming on Tuesday: “We’ll be bringing in measures to test people coming into this country to prevent the virus being readmitted.”

A senior aviation source told Travel Weekly: “UK citizens can’t travel to the EU anyway, but everything is on the backburner. We need to see what happens at the end of February now.”

A leading airline source described the lockdown as “a real setback”, but said: “It does reinforce the importance of pre-departure testing. The focus now will be on an effective restart. That is completely caught up with the restrictions, but we need to get our ducks in a row for when restrictions are lifted. We have to use this time wisely.”

The source added: “The new strain of the virus has really set things back. Without it we would have restrictions more coordinated. We’re weeks away from that now. The minute there was a new strain, health authorities [around Europe] just made their own decisions.

“Realistically, it will be the end of the winter schedule before there is any real [traffic] volume. There will be no half-term. However, with the vaccination programme, we were looking at April-May anyway.

“We’ve seen airline schedules contract and won’t see growth for the remainder of the winter. It’s a case of battening down the hatches.”

The source acknowledged differing rates of vaccination across Europe could impact the eventual recovery, saying: “We hope it won’t have a big impact on the outbound market, but it is going to be variable.”

In the circumstances, CAA confirmation just before Christmas that refund credit notes (RCNs) can be issued for cancelled packages up to January 31 was welcome.

A senior leisure industry source forecast “a lot of stuff through to Easter” will be cancelled this month and said: “All credit to the CAA. It will help the industry navigate this.”

Tui said it was “cancelling all holidays in line with international travel restrictions” and customers would be contacted “in departure date order to discuss their options”.

EasyJet Holidays said it was “reviewing all holiday bookings” and Jet2holidays extended its suspensions to the Canary Islands, Madeira and Turkey until February 12.

Abta said in a statement: “It’s right the government takes steps to control the spread of the virus. But this needs to come with measures to support travel businesses which have little or no means of operating. Support is long overdue from Westminster.”

Karen Dee, chief executive of the Airport Operators Association, described the lockdown as “a devastating blow” and said: “The government must urgently announce a comprehensive aviation support package.”

The chancellor did announce new grants for retail, hospitality and leisure businesses of up to £9,000, depending on rateable value, and an additional £594 million for firms outside these sectors in a package worth £4.6 billion.

But some agents said the grants did not go far enough in terms of their support as many businesses are facing no income as long as travel restrictions remain in place – while others have slipped through the cracks.

Speaking on BBC Breakfast on Wednesday morning, Advantage Travel Partnership chief executive Julia Lo Bue-Said said the industry was again facing “absolute turmoil”.

She said it was “frustrating” that a “vague comment” from the prime minister was all businesses had to work with to advise their customers.

“We still have no detail. It is really important they talk to us and liaise with us so we can help customers,” she told the programme.