Air travel into the UK has dropped substantially as 'travel corridors' between some destinations were scrapped over fears of mutant strains of coronavirus appearing round the globe. 

Flight tracking data shows that number of planes entering British airspace on Monday was well below traffic levels recorded just weeks ago. 

People entering the UK must now self-isolate for up to 10 days and have proof of a negative test for Covid-19 taken up to three days before they departed. 

The new rules have sparked a drop in passenger numbers, further impacting a bleagured travel industry.

The corridors were a lifeline for the travel industry when they were introduced in summer 2020, as struggling firms saw a spike in bookings for destinations added to the list.

But they were suspended from 4am as the Government attempts to prevent new strains of Covid-19 from entering the UK.

Meanwhile, passengers arriving to the UK on the first morning new quarantine rules came into force faced queues of more than an hour as official checks were made at the border.

Some of the earliest arrivals into London’s Heathrow airport said they had been met with “substantial” lines at passport control and one couple complained they had “felt unsafe” due to what they described as poor social distancing.

READ MORE: Passengers must self-isolate as 'travel corridors' scrapped

A ban on quarantine-free travel into the UK came into force at 4am in a bid to keep out new coronavirus strains – such as those which have been discovered in Brazil and South Africa.

The new rules mean arrivals from every destination are required to self-isolate for 10 days, or receive a negative result from a coronavirus test taken at least five days after they enter the UK.

Passengers flying in from overseas now also have to show proof of a negative Covid-19 test before setting off.

Foreign Secretary Dominic Raab said on Sunday that checks at the border would be strengthened as the new measures came into place.

But Andy Hart from London, who arrived into Terminal 5 with his partner on Monday morning from Nairobi, said he was “shocked and disappointed” to see the queues at passport control.

The Coffy app chief executive said: “We felt unsafe. We felt that even though everyone was masked they were far too close together.

“It took an hour and 10 minutes.

“I’ve been flying 30 times a year for 20 years. I mean, once or twice have I ever seen it (airport queues) like this.

“How can this happen during Covid times?”

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His partner, who did not wish to be named, said there should have been better staffing.

She said: “They knew today was going to be the switchover, so from 4am new rules came into effect.

“How come they didn’t have extra staff on standby?”

Richard Bradley also arrived from Nairobi with his son Joseph after a Christmas break with family.

Mr Bradley, who works in media and was returning to his home in Oxford, described the queue at passport control as “pretty substantial”, saying it took around an hour and a half to come through.

He said there was a “triple check” of people’s passports, proof of a negative Covid-19 test and their passenger locator form.

He said: “There were a couple of people in our queue whose tests may have been outside the required 72 hours so that was causing a lot of grief and discussion.”

An airport testing centreSome passengers were queueing for up to an hour (Kirsty O’Connor/PA)

Asked if those people were held back he replied: “There was a lot of discussion going on. I don’t know what happened.”

He described social distancing in the queue as “approximate” but added: “I think people are pretty mindful of not standing too close to each other.”

Bella Danquah, from London, said the rules on the 10-day isolation period could be made clearer for new arrivals.

The 34-year-old consultant who flew in from Accra in Ghana, said: “They just need to be clearer when people come in because not everybody is going to look at the (Government) website.

“I went on the website because BA (British Airways) told me to.”

She said officials should also tell passengers “when they were going through passport control”.