South East Coast Ambulance Service (SECAmb) said on social media that its staff and volunteers, 'in control and out on the road', faced a 'challenging evening'.
A spokesperson said: "We are working hard to reach all those who need us as quickly as possible but taking longer to reach some patients."
It comes as people across the South East are being urged by local ambulance leaders to make use of 111 online for medical advice, with demand for 999 calls increasing and ambulance staff helping more patients.
The 111 Online service offers patients quick advice on the best option for them to get the care they need, including getting a call back from a trained clinician or nurse, booking them an appointment in A&E or providing advice on how to help them recover.
Between July 16 and 23, SECAmb handled 25,599 calls – an average of more than 3,600 calls a day and some 24 per cent higher than a similar July week in 2019 before the pandemic.
Patients are also being urged to only call 999 back if their condition worsens – not to check what time their ambulance will arrive.
SECAmb medical director, Dr Fionna Moore said: “Our frontline ambulance crews, 999 and 111 call handlers and our dedicated volunteer community first responders are all working extremely hard to ensure we respond to patients as quickly as possible as we see increased demand for our services.
“As ever, we are prioritising our response to patients who are most sick and severely injured. Everyone who needs an ambulance will get one, however there are other and often better options for people to get the care they need.
“And as has been the case throughout the pandemic, the public can play their part by using 111 online for urgent advice, calling 999 in life threatening cases – and only calling back if their condition worsens – and by getting the covid jab.”
The public is still being encouraged to contact 999 if they experience; signs of a heart attack like a pain like a heavy weight in the centre of your chest or pain down your arm; signs of stroke such as your face drooping on one side; difficulty breathing; heavy bleeding that won’t stop; seizures or sudden and rapid swelling of the eyes, lips, throat or tongue.
National strategic adviser of ambulance services, NHS England and NHS Improvement, Anthony Marsh, said: “This is a really tough time for ambulance staff, who are working round the clock to deal with an increased number of calls, and I’d like to pay tribute to their continued efforts to ensure patients get the care they need.
“With pressure on services still high, the public can help us to help them by using 111 online to get medical advice, and of course the most important thing we can all do at the moment is get the Covid-19 vaccine – both doses – which protects us, our families and friends and will help to reduce pressure on the NHS as well.”
People can access 111 online at 111.nhs.uk