The average response time for officers dealing with the most serious 999 calls in Greater Manchester has almost doubled in seven years.
In 2018, police took nearly 12.5 minutes to respond to grade one-rated calls in comparison to under 6.5 minutes in 2011, new data has revealed.
An increase in recorded crime and a reduction in officers has been linked to the rise, Ch Supt Mark Kenny said.
He added police would always prioritise "the people who need us the most".
Figures obtained by the BBC also revealed an increase in response times for grade two-rated calls from around 48 minutes in 2011 to an average of 7.5 hours in 2017/2018.
Police 999 calls: What the rules say
Greater Manchester Police's incident response policy grades emergency calls on a scale of one to five, with targets for each category:
- Grade 1: Emergency response should be within 15 minutes of the call
- Grade 2: Priority response within one hour of the call
- Grade 3: Routine response within four hours
- Grade 4: Scheduled response or other resolution within 48 hours
- Grade 5: Telephone resolution
Despite the response times for the most serious calls still falling within official targets, some officers have expressed concerns.
PC Anthony Mack told the BBC the force was "struggling" and morale was low.
However, officers "were doing everything they can to make it work", he said.
The officer added: "When I started 11 years ago we would have had between 20 to 25 officers just based solely at West Didsbury Police Station. And now we have a bigger area to cover.
"We are also covering Levenshulme and Whalley Range, and we only have around 25 to 30 officers if everybody is in and fit to be deployed."
A Home Office spokesman said the government had "increased total police funding by around £970m in 2019 and 2020".
He added: "How these resources are deployed is an operational matter for the police".
Greater Manchester Police is currently operating with 2,000 fewer police officers than in 2011, as well as dealing with "a significant increase in recorded crime", Chf Supt Kenny said.
He added: "Unfortunately, this means that some victims won't receive the response they might expect, however we will always prioritise the service to the people who need us the most."