A backlog of passport applications is putting travel plans at risk, MPs and trade unions have warned.
Mike Jones, from the Public and Commercial Services Union (PCS), said: "There are half a million applications that are waiting within the Passport Office at the moment."
While the Passport Office aims to turn around straightforward renewals and applications within three weeks of approval, MPs have told of some constituents having to wait up to 16 weeks to receive their documents.
While a standard passport application costs £72.50, people wishing to fast-track the process and receive their passport within a week will pay between £103 and £111; while those choosing an ultra-fast one-day service must pay between £128 and £137.
While some recent examples have included people with non-straightforward circumstances - such as a pregnant lady living overseas – Her Majesty's Passport Office admits it has been busier this year compared to last.
It said it processed 300,000 more applications in the first five months of this year compared to the same period in 2013 but denies a backlog has formed.
Exceptional early demand
Paul Pugh, chief executive of Her Majesty's Passport Office, said: "We have issued almost three million passports for UK customers in 2014, including over one million issued in the eight weeks since the start of April.
"During this busy period we have processed more than 97% of straightforward passport renewal and child applications within the three week target turnaround time. There is no backlog — over 99% of straightforward applications have been processed within four weeks."
However he conceded that the service has experienced "exceptional early summer demand for passports, in part due to the improving economy and a rise in holiday bookings".
Staff were brought in immediately to respond to the extra demand, the office is operating seven days a week and its couriers are delivering passports within 24 hours of being produced, Pugh added.
Bob Atkinson, travel expert at TravelSupermarket, told Moneywise he has yet to receive a single letter or email from a consumer having problems with getting a passport and expects the problem to be a reflection of the time of year.
"We're coming into peak season for the travel industry and lots of people who have booked trips way in advance or at the last-minute are now scrambling to apply for, or a renew, a passport."
If you apply for a passport yourself it will cost from £72.50, but for anyone traveling within a month and in need of a new passport, Atkinson recommends using the Post Office's Check and Send service.
For £81.25 for a standard adult passport, the Post Office will ensure the application has been correctly filled in and all supporting documents have been provided before submitting it to the Passport Office.
This costs £8.75 extra compared to submitting the application yourself but it can save you time and hassle.
However, if you are running out of time to get the paperwork sorted because you are travelling within the next month, there's little other option to pay at least £103 for a fast-tracked application, which promises a one-week turnaround.
If you need a passport even faster, you'll have to stump up at least £128 for the premium one-day service and attend one of the Passport Offices in London, Liverpool, Peterborough, Glasgow, Newport, Belfast or Durham.
However, Atkinson added that if you've only got six months left on your existing passport – the minimum sometimes required to pass through customs, it's not always necessary to renew it before travelling depending on your return date and where you're travelling to.
For example, he told Moneywise, those travelling to the EU or US who will be returning to the UK before the expiry date of their passport, may be allowed to do so. "Just check with your airline first," he said.
Pugh at the Passport Office added: "We would remind people of our existing advice to customers: allow plenty of time when applying for a new or renewed passport as a passport will not be issued until the necessary security checks have been done, and do not book travel until you have received your passport."