The number of police firearms officers has fallen for the fourth year in a row, new figures have revealed.
There were 5,639 authorised firearms officers in forces across England and Wales as of March 31 - down by eight compared with the previous year when there were 5,647, Home Office data shows.
It means the number has dwindled by more than 1,000 in the last five years.
The disclosure comes at a time when Britain's armed policing resources are under close scrutiny in the wake of terrorist atrocities in Europe.
A drive to boost the service's firearms capacity was launched in the wake of the Paris attacks, with forces training hundreds of extra personnel as part of counter-terrorism efforts.
However, rank-and-file leaders have questioned where the additional personnel will be drawn from.
Che Donald, lead on firearms for the Police Federation of England and Wales, said: "The PFEW have repeatedly raised concerns around adequate numbers of firearms officers and we remain curious as to where this extra number will come from.
"While the argument for sufficient numbers to help manage any potential terror attack on UK soil speaks for itself, the support firearms officers give to our unarmed colleagues is just as important."
The Home Office said the figures do not include the uplift in armed policing capability to be delivered over the next two years.
A spokeswoman for the department said: "It is for operationally independent chief officers to determine the number of authorised firearms officers in their areas based on a thorough assessment of threat and risk.
"Following the Paris attacks last year, the Government announced that £144 million will be provided over the course of the Spending Review period to uplift armed policing capability and capacity in order to respond more quickly and effectively to a firearms attack.
"It will mean more than 1,000 additional armed police, round-the-clock specialist teams being set up outside London and 40 more Police Armed Response Vehicles on our streets."
The National Police Chiefs' Council said police are still on track to deliver an extra 1,500 firearms officers over the next 18 months.
The body's lead for firearms, Deputy Chief Constable Simon Chesterman, said: "Following the recent terrorist attacks in Europe and escalation of the terror, we assessed our ability to respond to similar attacks in the UK and committed ourselves to recruit and train more armed officers to strengthen our response.
"Our recruitment and training programme is now well under way. This is a rolling programme with the majority of new firearms officers to be trained and deployable by April 2017.
"We are on schedule to meet our targets."
He said recruitment to the roles "will be a challenge", adding: "New authorised firearms officers will be existing police officers who volunteer for a highly responsible and dangerous job to protect the public.
"Armed officers accept the high levels of accountability that come with the job however, they should be recognised as highly trained professionals who were carrying out their duty on behalf of the state, with the intention of protecting the communities they serve."
There were a total of 14,753 police firearms operations in the year ending in March, a slight increase of 68 compared to the previous year.
There were seven incidents in which police discharged firearms - one more than in the previous year.