The fire service took longer to reach the most serious fires last year, leaving ‘lives and businesses at risk’.
Firefighters took more than half a minute longer to respond to serious fires compared to five years ago, according to Home Office figures.
Crews took an average time of nine minutes and 13 seconds to reach the blazes, which the Fire Brigades Union (FBU) says is 'incredibly alarming'.
FBU general secretary, Matt Wrack, said: "In a fire, a matter of seconds could be the difference between life and death, so these figures are incredibly alarming.
"Services have been cut to the bone, and it's obvious that with fewer firefighters and scarcer resources, firefighters are taking longer to get to fires, putting lives and businesses at risk."
The Home Office says a rise in response times was caused by an increase in average drive time, such as changing traffic levels.
Avon Fire and Rescue Service has made a number of changes to improve its response times since last year.
Assistant chief fire officer Simon Shilton, said: "Since the implementation of our service plan last April, we have made significant strides to ensure our resources match our risk with two key themes - making our communities safer and service stronger.
"As part of that, we are set to launch new response standards this April which will see a change from geographic and population based response to a categorised response based on risk.
"We are aiming to reduce the high level of Automatic Fire Alarm (AFA) calls we currently attend, 97 per cent of which are false alarms, as this will free up a large drain on our resources, taking firefighters away from lifesaving activities or risk reduction work in the community.
"We have undertaken a thorough review of our fleet to ensure the best use of our vehicles and have purchased seven new narrower and shorter fire appliances, the first of which will be delivered later this year.
"This will ensure we can better deal with congested streets across our service area.
"Finally, as part of our Investing in the Future Programme, we have an ambitious capital programme to invest in and future proof our buildings at Avonmouth, Bath and Weston. This will ensure they are fit for purpose and crews able to respond in the most effective manner possible."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here