Half of ambulance patients waited more than an hour to be handed over to accident and emergency services at the Dorset University Hospitals Trust last week, new figures show.
The Royal College of Nursing, a staff body for the profession, said the healthcare system is "dangerously close to overheating completely".
NHS England figures show 409 (50 per cent) patients waited in an ambulance for at least one hour when they arrived at University Hospitals Dorset NHS Foundation Trust A&E in the week to Sunday December 18 – up from 336 (41 per cent) the week before.
Read more: What University Hospitals Dorset is doing to ease pressure on NHS
A further 154 patients were forced to wait between 30 minutes and one hour, meaning 69 per cent of the 817 total ambulance arrivals were delayed by half an hour or more, and at least 1,583 hours were lost.
The figures cover the week before a 24-hour strike by ambulance staff across England and Wales over complaints of poor working conditions and pay.
NHS targets state trusts should complete 95 per cent of all ambulance handovers in 30 minutes, with all conducted in less than one hour.
More than 16,300 handover delays an hour or longer were recorded across all hospital trusts last week, according to NHS England – up 31 per cent from 12,500 the week before.
Read more: Busiest and quietest times at A&E in Bournemouth and Poole
A handover delay does not always mean a patient has waited in the ambulance as they could have been moved into an A&E department but the handover was not completed.
Ambulance staff walked out on Tuesday, December 21, and are expected to do so again on December 28.
Further strike action by staff at five ambulance services on January 11 and January 23 was also announced by trade union Unison this week.
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