Abta’s intervention comes after the government last week conceded some UK airports wouldn’t meet its 1 June deadline to introduce next-generation scanners, which will allow passengers to carry liquids in excess of 100ml in their hand luggage for the first time since 2006.

Once the rollout is complete, they will also allow passengers to leave their electronic devices in their bags when they pass through airport security.

Several airports have completed their upgrades, including Teesside airport – which was the first to do so – and also London City airport. Others, though, are expected to miss the deadline, including some major airports.

The government has granted a number of UK airports up to another year to upgrade their security arrangements, and is threatening to impose strict financial penalties if they fail to hit their new targets.

Abta on Wednesday (10 April) said that owing to the "lack of consistency" across UK airports, it was advising agents and holidaymakers to prepare for the existing rules to apply such as by sticking to the 100ml liquid limit and removing electronic devices from hand luggage before arriving at airport security – whether the new rules are in place or not.

In addition, Abta is urging agents and travellers check the rules for destination airports, warning that even if people able to leave the UK under the new rules, their destination airport may not have the same technology in place.

Abta has launched a new advice page at abta.com/airportsecurity to offer clarity and advice. Last week, Advantage Travel Partnership chief Julia Lo Bue-Said said the delay risked "significant disruption" to the summer getaway if passengers don’t get "the necessary guidance" before they travel.

‘Clarity needed’

“What travellers need now, as we head towards the peak months for overseas travel, is clarity about what to do when going through airport security," said Abta’s director of public affairs, Luke Petherbridge.

"When fully implemented, the new airport scanners will make things faster and strengthen security. However, the recent extensions from the government show that there is still some way to go before the new security rules are consistently in place across UK airports.

"With that in mind, our best advice is to prepare for your travels with the existing rules in mind. That way, you’ll be ready to comply whatever the scenario, avoiding any unnecessary delays through security and any difficulties when returning from your destination. You can also check with your airport in advance – and we’d also recommend checking with your return airport too."