Britain's armed forces are suffering their biggest staffing crisis in years, with the vital area of intelligence analysis being one of the worst affected sections.

The National Audit Office, which regulates government spending, has published a report revealing that the number of full-time military personnel is 5.7 percent, or 8,200 people, below the required level. Most alarmingly in an era of new challenges such as cybersecurity, the shortfall in intelligence analysts is 26 percent.

Meg Hillier, the chair of the public accounts committee, said the report showed the armed forces to be "woefully below compliment, especially in crucial areas like intelligence and engineering", adding that "the Ministry of Defence needs to take a long hard look at its current approach".

The report picked out six key areas - engineering, intelligence, logistics, pilots, communications and medical - which were particularly affected. Within those, there were 102 trades identified where the military is not deemed to have sufficient trained staff to perform operational tasks.

The strategic defense and security review of 2015 set increased targets for many intelligence analyst roles, with some in the Royal Air Force being doubled or even trebled. The nature of newly-emerging threats means intelligence demands, such as language skills, can change rapidly, making training particularly challenging.

The report warned that the MoD's "base-fed" model "where it recruits regulars into the lowest ranks and develops their skills and experience over time has not enabled it to close capability gaps quickly enough", and warned that it was "not a sustainable long-term solution".

Other findings included a shortfall of 2,400 engineers, most substantially among Royal Navy weapons technicians, 800 pilots and 700 intelligence analysts.

The report backs up concerns raised a year ago by former Armed Forces minister Mark Francois in a report on recruitment. This found that in the year to April last year, 12,950 recruits joined the regular armed forces, but 14,970 had left.

"This continuing process of 'hollowing out' in the ranks," the report said, "while costing the armed forces valuable experience, also threatens to compound the problem by increasing the pressure on those personnel who remain."

Responding to the issues, an MoD spokesman said recruiting and retaining talent was a top priority, and that a range of schemes to attract and keep skilled personnel was in place, including special retention payments for intelligence staff.

"The military has enough personnel to meet all its operational requirements, including being active on 25 operations in 30 countries throughout the world," the spokesman added.