article_snippet.sent: The boxes of passport applications piled up at in office in Liverpool at the peak of the backlog last summer .
article_snippet.sent: The problems began a year ago as HM Passport Office struggled to cope with 3.6 million Britons applying for documents.
article_snippet.sent: By mid-June there were more than half a million passports stuck in the system.
highlights_snippet.sent: HM Passport Office struggled to cope with 3.6million Britons applications .
  