The number of police firearms officers plunged by nearly a fifth in five years, new figures have revealed.
There were 5,647 authorised firearms officers (AFOs) in forces across England and Wales as of March 31 last year, Home Office data shows.
It means the number fell by more than 1,300 personnel, or 19%, compared with five years earlier, while it was also down by 217, or 4%, on the previous year. It is also the lowest level since the current data set started in 2009.
The report said: "The number of AFOs was at its highest on 31 March 2010 (6,976) and has since been on a general downward trend."
The disclosure comes at a time when the police service's firearms strength has come under close scrutiny in the wake of terrorist atrocities in Europe.
Earlier this month Prime Minister David Cameron announced that more armed officers are to be stationed across the country to deal with a Paris-style attack.
Forces are training around 1,500 extra armed officers as part of counter-terrorism efforts, with 400 ready to be deployed to cities outside London around the clock.
However, rank and file police leaders have questioned where the extra personnel will come from, while there have also been calls for a review into the legal protection for firearms officers amid suggestions this is an issue in recruitment.
The figures also revealed that there were a total of 14,666 police firearms operations in the year ending March 2015 - a decrease of 2% (273) compared with the previous year.
There were six incidents in which the police discharged firearms in the year ending March 2015, up from two in the previous year.
Simon Chesterman, the National Police Chiefs' Council lead for armed policing, said: "The fall in the number of authorised firearms officers over recent years reflects the fact that forces in England and Wales have moved to more collaborative arrangements, with armed officers working regionally rather than in individual forces.
"Decisions on numbers were based on local threat and risk assessments.
"The arrangements have maintained an effective armed policing capability to protect the public in all areas of the country, as well as enabling forces to make efficiency savings in response to budget cuts."
He added: "Following the terrorist attacks in Paris and Brussels, we closely examined our ability to respond to a similar attack in the UK and determined that we needed to recruit and train more armed officers to meet the escalation of the terrorist threat.
"Several forces have recently announced plans to increase their number of AFOs and the Government has provided additional funding. Together this national and local funding will deliver an extra 1,500 officers over the next 18 months."
He said recruitment to the roles "will be a challenge".
"New AFOs will be existing police officers who volunteer for a highly responsible and dangerous job to protect the public," Mr Chesterman said.
"These officers will want reassurance that in the rare event that they discharge their weapons they will be treated as highly trained professionals who were carrying out their duty on behalf of the state, with the intention of protecting the communities they serve."
Shadow police minister Jack Dromey said: "According to the Home Office's own data, 1,329 firearms officers have gone in the five years since Cameron became Prime Minister.
"Police leaders have said time and time again that, without sufficient firearms capability, we would struggle to cope in the event of a terrorist attack.
"The Tories need to put the safety and security of our country first, properly funding the police service and the vital role of firearms officers."