Citing Border Force sources, the paper says tax officials have been given 10 days’ training to help check passports, although they will not be able to check those of non-European passengers.

Travellers arriving in the UK have reported significant delays at passport control in recent months, with Heathrow and Luton being among the highest profile flashpoint.

The Times’ source added the Border Force was currently “in the grip of a staffing crisis”.

The government currently targest getting non-EEA passport holders through immigration in less than 45 minutes 95% of the time.

However, according to leaked figures seen by the paper, that target was missed nearly 2,000 times at Heathrow in June - up from around 1,300 in May.

Terminal 5 only met the target 76% of the time in June.

Bar UK, the group representing scheduled airlines operating in the UK, said regular reports of two-hour queues at border control was of “extreme concern”.

The Home Office said it was aiming to recruit up to 1,000 new Border Force officers by next March.