Border Force officers have been ordered to “deprioritise” customs work at airports such as searching for guns and drugs in order to stop passport queues frustrating travellers. Leaked emails show that staff at Manchester airport were told this month that customs work should be carried out only if “there is no likelihood of an excessive queue time”. It meant there would be no spot-checks for illegal firearms, offensive weapons or drugs by customs officers, sources said. Searches could be initiated by intelligence-led work such as a category A order – a rare response prompted by intelligence from the National Border Targeting Centre. The Guardian understands staff have been under intense pressure from ministers to keep queues moving swiftly, particularly during half-term in parts of the UK. Staff at Heathrow said they had also been told not to work “proactively’ on customs during the February school holiday. The disclosures came as Home Office sources said there was increasing concern within government that there would be another Easter and summer of chaos at UK ports and airports. It follows a highly critical review last year into Border Force by Alexander Downer, commissioned by the former home secretary Priti Patel. The review concluded that Border Force’s work to prevent the entry of firearms and class A drugs had been “diluted”. The leaked email was sent by a named assistant director at the Border Force on 9 February, days before many school holidays began. “I want to confirm the steps we need to take to stabilise the PCP [primary control point] excessive wait times and to make the best use of the resources we have available to secure the border,” the email said. “With immediate effect I have asked the ADs [assistant directors] to implement the following: Any staff who are contingency trained should be prioritised to the PCP [Primary Control Point] when required to prevent excessive queues. Customs work is deprioritised and will only be carried out when you are satisfied there is no likelihood of an excessive queue time or in the event of a cat A target,” he wrote. At Heathrow, staff said they were also diverted on to passport checks. “The priority was to make sure people getting away and coming back from their holidays – many were going skiing – did so without interruption.” Downer’s report criticises the customs training for Border Force officers, saying it was completed on the job and had been downgraded. Customs checks were being abandoned as Border Force staff working at regional hubs were being diverted to busier ports such as Heathrow, he said. “Border Force send staff from all over the UK to manage shortages at Heathrow and ports in the south-east of the country, taking staff away from their home ports, reducing resilience at those ports and the ability to perform discretionary but important work that the public expect from Border Force such as customs checks in passenger channels at airports,” the report says. Last year, the independent chief inspector of borders recommended that the Home Office review its practices to ensure it covers customs checks after an inspection at Birmingham airport revealed that there were no Border Force staff working on customs because they had been diverted to passport controls to ease queues. David Neal, the chief inspector, recommended that the Home Office review checks to maintain adequate coverage of both areas or risk leaving the borders at risk to organised crime. “It was alarming to discover that no Border Force staff were present in the customs channels during the course of our inspection. Instead, officers were deployed to passport control to prevent the buildup of long queues,” he said. At the time, the Home Office partially accepted Neal’s recommendation, and said in a statement that “Border Force’s workforce planners are working closely with front line operations to model and review the numbers of staff needed in each port to provide sufficient coverage for all mandated activities including immigration and customs checks”. Responding to the leaked email and claims from Heathrow, Home Office sources said the email had been taken out of context and customs work had continued as usual. A Home Office spokesperson said: “Border Force’s number one priority is to keep our borders safe and secure for all passengers, and we will never compromise on this. “During peak periods, resources are continually assessed to balance all pressures. Resources are deployed dynamically through intelligence and data to intervene any potential threats.”