The Prime Minister "shares the concerns of families" about delays in the processing of passport applications, his official spokesman says.
He told a Westminster briefing that David Cameron: "very much understands concerns about the delays that people have been experiencing", adding "that is why it is absolutely right that additional measures have been taken."
The spokesman said that the number of applications for passports in the early months of this year was more than 10% up on the same period of 2013.
"We will continue to stay very vigilant on this, because families shouldn't face delays," he said.
The Home Office has outlined how people who are facing delays to their passport renewal can get it fast-tracked for free.
If you are worried about your passport application not being ready ahead of your holidays, there are a few options available to you.
Photos shown to ITV News appear to reveal the scale of the backlog at the Passport Office, amid staff claims of "blind panic".