Nick Barton told Sky News staffing levels were still "about 15% short", citing a 10-12 week process for new recruits to complete their training and receive the necessary security clearances.

Chief executive Barton’s warning on Friday (27 May) comes after months of disruption at UK airports, which are struggling to recruit sufficiently to meet post-Covid passenger demand, now the UK’s inbound travel restrictions have been all-but completely lifted.

Last month, transport secretary Grant Shapps said the government would lay new legislation to allow airports to start training new staff while they await security clearance.

Currently, this screening takes place before any training can begin. Shapps said while he couldn’t compromise security, he believed it was an area where the government "could assist with the bureaucracy".

Barton said Birmingham got about two to three days’ notice that the UK’s inbound travel restrictions would be lifted on 18 March. "In simple terms, the airport was operating at about a third of what it used to do, and had been for two years, so we lost half of our staff," Barton told Sky News.

"The demand for, and the appetite for, aviation was switched on in February and March, and came back almost immediately, and we then had to race and catch up. For that simple reason, the queueing and the service levels that we’re used to giving simply couldn’t be met."

Barton revealed 43% of Birmingham airport staff were made redundant during the pandemic, adding recruitment at the back end of 2021 was hampered by the onset of the Omicron variant of Covid-19. He said it wasn’t until flight traffic recovered in February that the airport was able to start recruiting again in numbers.

"We expect the summer to be really busy," he continued. "We’ll be largely back where we want to be through the middle of August. In terms of getting ourselves back to normal fully, [it’s] probably September, October."

Barton said staff had been working overtime to meet demand, himself included, adding he had been doing early-morning security shifts.