Concern has been raised after latest figures show that the percentage of ambulances arriving at the scene of an emergency within eight minutes in Powys has decreased from 66.1% in March to 56.1% in April.
The statistics, published by the Welsh Government, has prompted one local politician to call for more support to the hard working local health service.
Russell George, Assembly Member for Montgomeryshire, said: “In spite of the continued hard work of healthcare professionals and ambulance staff, the sharp deterioration in ambulance response times for life-threatening calls in Powys is concerning.
"Ambulances queuing at emergency departments is also unfortunately becoming a common sight across Wales, indicative of a poorly managed health service in desperate need of revitalisation.
"The Welsh Government must recognise the consequences of poor ambulance performance on rural Wales in particular and do more to ensure that patients in life-threatening situations receive a consistent, high quality service wherever they live.
"This postcode lottery must stop and there is a clear need to invest in and modernise our ambulance services to ensure they are fit for purpose.
"Poor ambulance response times are putting people’s lives at risk. The answer to sustained improvement in performance and greater accountability does not lie in the Welsh Government’s approach of moving the goalposts and record breaking NHS budget cuts; instead we need to see extra investment in the Ambulance Service."