Paramedics serving the South East have said they believe the ambulance service is becoming increasingly overstretched.
Ambulance staff from the South East Coast Ambulance Service (SECamb) said cost-cutting measures have led to slower ambulance response times.
But management said SECamb had met its emergency response time target for the past four years.
Senior operations manager James Pavey said: "We do get to more people more quickly than we have ever done before."
The ambulance trust serves 4.5 million people across Kent, Sussex and Surrey.
It is aiming to save about £40m over the next five years as part of the NHS's national commitment to find £20bn savings.
Ambulance technician Jamie Dixon said: "I've been in this job 10 years and I've noticed in the last year that our journey times have been getting longer and longer.
"I can only put that down to less resources on the road or more calls coming through to the ambulance service every day."
Ben Sylvester, a senior paramedic, said: "We want to do the best for the patient but sometimes we feel that we're being let down by what could be said is a cost-cutting exercise.
"We see it at the coalface as a lack of resources available to our patients and it has the potential of being at the detriment of the patient and could put lives at risk."
Mr Pavey said patients in the South East received an excellent service.
He said: "It would be wrong to say that the ambulance service isn't challenged all the time.
"What we try to do and what we have done successfully is to try and meet the demand as best possible."
The government target is that 75% of life threatening emergencies have to be reached within eight minutes.