The East Midlands Ambulance Service operations director has accepted emergency response times in the region are not good enough.
The service failed to hit 24 of 32 response time indicators in 2013. It failed to achieve any in the last six months of the year.
One in three patients had to wait more than eight minutes for an ambulance in December, which significantly short of the minimum national standard, which is for no more than a quarter of patients to have to wait that long.
In Northamptonshire, the picture is worse, with ambulances arriving within eight minutes at just 61 per cent of the most serious incidents.
The county figure did improve in January but fell again last month to 63 per cent.
Across the region, EMAS has not hit a national standard of reaching 95 per cent of patients within 19 minutes since March last year.
Ambulance service interim director of operations Richard Henderson, said the figures did not show that most responses are a matter of seconds outside the target.
The average response time in the county is eight minutes and 27 seconds in the most serious cases.
Mr Henderson said: “That’s how tight it is at the moment.
“We are talking seconds, it’s not like we are a long way out. We are changing our dispatch framework and we are continuing to recruit more staff, working with the health community to make sure we have got plans in place to support us.”
There have been nine emergency care assistants and four paramedics recruited in Northamptonshire since January, and Mr Henderson said he believed a new quality improvement plan would result in better performance.
He said: “As an organisation we have been under considerable scrutiny. The commissioners have got confidence in the plans. We have got robust plans in place.
“Anywhere we are not delivering national standards is not good enough. We recognise the requirement to improve our position.”
Dorothy Maxwell, of Rushden, who organised a 100,000-signature petition to campaign against the threat of ambulance station closures in Northamptonshire, was disappointed response time targets were still not being met.
She said: “I’m shocked. I am really sad that we are going backwards not forwards.
“A lot of people will be shocked that responses are so poor. The population of Northamptonshire has increased – is the ambulance service keeping up?”
She said she would write to health secretary Jeremy Hunt to express her concerns.