London Ambulance Service trust has promised action after admitting that it has failed to meet 'even modest performance targets' and cannot always provide a clinically safe service.
An improvement programme drawn up ahead of a recent board meeting admits that just 40 per cent of emergency patients are reached within the government's eight-minute target.
It also says patients picked up by LAS after suffering a cardiac arrest have only a 2 per cent chance of being alive one year on.
The trust was due to appoint a substantive chief executive today, filling the post Michael Honey left six months ago.
Speaking to HSJ this week, acting chief executive Peter Bradley said the programme 'without doubt' sets out a stall for extra funding. LAS estimates it needs£26m to 'turn the service around'.
But Mr Bradley said managers also recognised that 'in various ways the service has to change the way it is run'.
The report says cutting 'excessive' use of frontline ambulances needs 'urgent attention if clinical risk is to be reduced'.
This will mean targeting staff on the busiest areas, increasing the number of staff and vehicles, and introducing paramedic telephone advice and decision-support tools.
Mr Bradley said government targets to respond to 75 per cent of category A calls in eight minutes should be 'achievable' under the improvement programme. But he said ultimate targets of reaching 90 per cent of such calls would be 'much, much more difficult'.
The programme compares LAS's cardiac arrest survival rates with 'world-class service' survival rates of between 15 and 20 per cent after a year.
But Mr Bradley said higher survival rates in places such as Helsinki, Sydney and Seattle were linked to public awareness of resuscitation techniques and more widespread access to defibrillators.
The programme sets out 70 pieces of work to be carried out over the next four years, and calls for 'strengthened management'.
It also aims to tackle staff issues which have dogged the trust, 'to move from a culture of blame and defensiveness to one of mutual trust and professional respect'.
Last week the trust began a round of 30 meetings with staff to consult on the programme, ahead of publication of a full action plan in October.
Mr Bradley said a staff survey in May had found widespread unhappiness among workers.
'They don't feel they know where the organisation is going. They don't feel they are paid enough. They don't feel they are valued. They don't feel they are kept informed.'
But as consultation began, LAS Unison members were threatening strike action after claiming that staff are being denied leave over the summer.
Branch secretary Eric Roberts said that rota arrangements had been changed without reference to staff, and that managers had acted 'without honour' by breaking an agreement set in place 13 years ago.
But the trust insisted that the rules were unchanged. A spokesperson said that no leave had been blocked, and that any requests for leave turned down related to 'ad hoc ' days off.