The Fire Brigades Union said that an increase in fire deaths across the country showed that services are in "crisis".
New Home Office figures show that five people died at home and one outdoors, in incidents attended by the Lancashire Fire and Rescue Service between July 2017 and June 2018.
Across England, there were 247 fatalities recorded over the 12 months.
The FBU said that years of cuts meant a downward trend in fire deaths had stalled in recent years, with one in five firefighter jobs lost since 2010.
Dave Green, the union's national official, said: “The Government continues to bury its head in the sand with regard to its responsibility for the Fire and Rescue Service. They have stripped it of central funding and then pushed the blame to local authorities.
“The reality is the service is in crisis. Firefighters don’t have time to give routine fire safety advice, to do safety inspections on premises and are having to cope with attending emergencies with fewer and fewer resources.
“This situation cannot continue and all responsible politicians need to address this as a matter of urgency. The tragedy is that a service that was once the best in the world is being dismantled before our eyes by this uncaring Government”.
There were also 429 fire-related casualties recorded in Lancashire over the past 12 months, most commonly occurring in homes.
Of all casualties, 19 were severe. A further 72 required hospital treatment for minor injuries.
A Home Office spokesman said: “The Government recognises the vital role firefighters continue to play in protecting communities.
“Over the past 10 years the total number of fire incidents in England has nearly halved – down 46pc – and work to prevent fires from starting in the first place has seen real success.”
The figures also show the work done by the Lancashire Fire and Rescue Service in preventing fires. In the 2017-18 financial year, they carried out 11,954 home fire safety checks, mostly for elderly and disabled residents.
They also carried out more than 11,209 hours’ worth of campaigns to alert people to the importance of fire safety.