The Immigration Services Union (ISU), which represents border and immigration staff, has warned that there could be delays of between two and six hours, as their members have to check that every traveller has the correct Covid-19 documents.

Shapps told BBC Radio 4 that the experience for travellers going through airports and other ports would be “undeniably more disruptive than it would have been in years gone by”.

“The issues are probably going to be actually on the check-in side rather than the border side at Heathrow and elsewhere,” he said. “That’s because carriers are the ones who need to do these checks at the check-in point and that’s where the queues may well develop.

“They are looking at digitalising a lot of that, as usually people check in away from the airport – that could help.

“It’s going to be more disruptive than 2019 clearly, but we have an important job to do to keep coronavirus under check. We will be working hard to reduce the queues.”

Shapps added that e-gates in airports were also starting to be able to deal with the passenger locator form that arrival passengers are required to complete.

He also said passengers were likely to face longer delays at overseas airports rather than when they get back to the UK.

The ISU’s professional officer Lucy Moreton told the BBC that it took “three or four” times longer for border staff to check a passenger’s Covid documentation than the usual immigration process.

“It takes two to four minutes to check they are who they say they are, but eight to 12 minutes to check the four bits of paper or electronic bits of paper [for Covid],” she added.