An under-performing NHS trust has pledged to continue to reduce the amount it spends on private ambulance cover after new figures revealed that it had halved monthly costs since April.

The East of England Ambulance Service came under fire earlier this year after it emerged that it had spent £12.8m last year on private ambulances.

Campaigners last night welcomed news that the NHS trust had slashed its monthly expenditure on private providers since the publication of the organisation’s turnaround plan.

Andrew Morgan, interim chief executive, pledged in April to reduce private ambulance expense by £500,000 a month as part of a plan to improve performance.

Figures released by the trust under a Freedom of Information request show that the trust spent £1.9m in March and £1.3m in April compared with £990,484 in August and £757,999 in the month of September on private providers of emergency ambulances and patient transfer service contracts.

In the first six months of 2013/14, the trust spent £5.7m on private providers across the six counties it serves.

Officials from the East of England Ambulance Service said they would continue to attempt to reduce costs. However, winter pressures may mean that private ambulance fees rise.

Rob Ashford, acting director of service delivery, said: “We’ve been working incredibly hard as a trust to reduce the amount we spend on private ambulance services (PAS) as promised in our turnaround plan.

“One of our newest developments is the use of agency paramedics to staff our vehicles. This has helped us lower our PAS spend as rather than hiring staff, vehicles, and equipment, we are solely hiring staff.”

Denise Burke, of the Act on Ambulances campaign, welcomed the reduction in private ambulance spending.

She said: “I am encouraged by the fact that the figure is falling on private ambulance costs and they are moving towards their target because we had concerns about quality and they did not have the right communications with hospitals and control rooms.

“However, we know the new staff are not there yet and if response times are not coming down, it probably means that staff are doing more overtime.”

The East of England Ambulance Service paid out more than £12m in 2012 on staff overtime, but has pledged to recruit 350 front-line staff this year to get more double staffed ambulances on the roads.