Travellers have complained about “total chaos” at airports with hundreds of thousands of people jetting off as schools close and summer holidays begin for millions.

Airports and airlines are expecting their busiest weekend of the year, with Heathrow Airport expecting to welcome about 128,000 passengers on Saturday and Sunday, down from pre-pandemic daily volumes of around 230,000 to 260,000 in July 2019.

Its chief executive John Holland-Kaye said additional staff would be on hand to ensure passengers have a “smooth journey”.

But Fiona Brett, a violinist travelling to Frankfurt with the Chamber Orchestra of Europe, said she had to queue for two hours to check in to her flight from London Heathrow on Saturday morning.

Ms Brett, from Watlington, Oxfordshire, said she had checked in online but then had to show her Covid vaccination certificate to staff, adding that the “total chaos” resulted in her 9.30am flight being delayed.

“They were constantly calling people out of the queue for the next flight that was closing,” she told the PA news agency.

“Actually it would have been better to turn up at 8.30 and get called from the back of the queue to the front – total chaos.

“When I finally managed to check in (15 mins after the flight should have closed) the security queues were non existent and there was virtually no one airside in the terminal.

“I believe the queues were caused not by too many people but by the airlines having to do all the extra checks before properly checking in.”

Other passengers took to social media to complain about queues at London Stansted, with one describing the scenes as “chaotic”.

Twitter user Dr Robert Baunsbak Coull said: “@Ryanair totally unacceptable scenes at Stanstead Airport with total lack of staff on the ground, queues of lost passengers and chaotic scenes. #superspreader #covid19.”

Another Twitter user, Lily McMyn, posted images of crowds of people and added: “@STN_Airport shocking, chaos and bedlam.”

Manchester Airports Group said it is expecting 958 flights at Manchester Airport from Friday to Monday, 224 at East Midlands Airport and 1,330 at London Stansted.

This is up from the 632, 177 and 735 respectively during the same weekend last year, but still well below the 2,512 at Manchester, 503 at East Midlands and 2,139 at London Stansted in July 2019.

Meanwhile Gatwick Airport said it expects to see around 250 to 260 flights and between 25,000 to 27,000 passengers a day over the weekend, up from a low of just 15 flights a day at the height of the pandemic.

The airport said flight numbers are still far below the 950 per day at this time of year pre-Covid.

A spokesman said: “Our passengers are now able to choose from flights to more than 100 destinations in over 30 countries so we’re expecting our busiest weekend of the year so far.

“We will handle over 250 each day, with locations in Spain and Greece particularly popular.”

Airline easyJet said it is preparing to carry more than 135,000 passengers this weekend from the UK on over 80 routes to green and amber-list destinations across Europe.

In total there will be 251 easyJet flights taking to the skies, with popular destinations including Malta, Madeira, Malaga in Spain, Faro and Lisbon in Portugal, and Corfu and Athens in Greece, the airline added.

Ali Gayward, easyJet’s UK country manager, said: “With schools breaking up for summer, this weekend sees the busiest weekend so far this year and we are looking forward to taking as many people as we can on that long-awaited and well-deserved trip, or to reunite them with their loved ones.”

Tui said it has almost double the number of passengers travelling Friday to Sunday compared to last weekend, with the Balearics and Greece the “clear favourites” and Palma, Ibiza and Rhodes the most popular destinations.

Jet2 said it has 170 flights departing to more than 40 destinations over the weekend, up from around 70 to six places the previous weekend.

Since May, quarantine and testing requirements have been determined by whether a person is entering the UK from a green, amber or red list location.

Travellers returning from a green destination are not required to self-isolate, but only a handful of major European summer hotspots are in that tier.

Spain, Italy and Greece are among the countries on the amber list.

Those returning from an amber country must quarantine at home for 10 days unless they have had both doses of a coronavirus vaccine.