We are demanding that HMPO
enters into substantive talks over its proposals and that the plans are scrutinised by parliament.
spokesman said: "Every application is subject to the necessary checking procedures in order to maintain the integrity of the passport and to ensure passports are correctly issued to the right people.
In addition, HMPO had agreed to drop the PS55 fast-track processing fee for applicants who needed to travel urgently while people applying to renew passports overseas for travel to the UK would be given an automatic 12-month extension.
But while Mrs May said the measures would help ease the pressure, she warned there was no quick "big bang, single solution" and that Home Office permanent secretary Mark Sedwill will carry out a series of reviews into the way HMPO was operating.
In the medium to long term the answer is not just to throw more staff at the problem, but to make sure HMPO is running as efficiently as possible and is as accountable as possible," she said.
The HMPO has now called on holiday-makers to submit their applications in plenty of time in a bid to avoid being left unable to travel.
Paul Pugh, HMPO chief executive, said: "We are urging travellers not to forget the most important item on their travel checklist - their passport.
Extra staff are employed by HMPO during summer months, but there are limited numbers of appointments at passport offices for fast-track and premium services.
on twitter LIVECHONEWS Staff are being redeployed from non-operational posts within HMPO
and the visa and immigration service to help.
I d like to take this opportunity again to thank Paul and all the staff at HMPO for the huge effort put in to responding to what was a very challenging situation.
HMPO ceased to be an Executive Agency from 1 October 2014 when it was brought into the Home Office and made directly accountable to Ministers.