Holidaymakers are being urged to get new passport requests in early because processing could take as long as ten weeks.
That means anyone applying for a passport or renewal now will be unable to jet off for a Whitsun break next month.
And they should not expect to receive a new passport until towards the end of June.
The hold-ups are being blamed on a backlog of Covid applications as people are allowed to travel again and a shortage of passport workers because of the Ukraine War.
An insider said: “Many of our staff have been seconded to deal with visas for Ukrainians.
“Processing those is now our top priority so we can get as many as we can to safety.”
The Passport Office deals with seven million applications during a normal year but that dropped to four million at the height of the pandemic when travel was banned.
Now officials are bracing themselves for a sudden influx of five million applications from 2020 and 2021 as people plan Summer holidays.
Shadow Home Office minister Stephen Kinnock said: “Time and again Priti Patel ’s Home Office messes things up and fails to put proper plans in place.
“These are completely unacceptable delays. British families shouldn't be missing out on hard earned breaks because the Home Office didn’t plan.”
The Passport Office is also warning that availability for in person appointments for last minute travel will be limited.
Passport Director General Abi Tierney said: “Many people are leaving applying for a passport too late.
“Summer holidays are fast approaching so if you need a new passport we urge you to apply now.”
Last month new passports were being turned around in six weeks and renewals in five but now that looks set to double.
It is in sharp contrast to the two week turnarounds Passport Office boss Mark Thompson demanded of staff in 2018. He left in 2020.
A spokesperson for the Association of British Travel Agents said: “We are encouraging people to renew or apply as early as possible so they have their passport in good time for their trip.”
There were also warnings of 10 week delays at the height of the pandemic.
