Mothers get an inferior service from the NHS when they give birth at night because junior staff on duty then make poor decisions about their care, Britain's top maternity doctor warns today.

The inexperience of doctors working night shifts in labour wards can mean they lack the skills needed to ensure a baby's safe delivery, that women have unnecessary caesarean sections and that some babies suffer catastrophic harm during their birth, Dr Tony Falconer claims.

"Obstetric care isn't the same at 3am as it is at 3pm, and it should be. This is a matter of huge concern," Falconer told the Guardian in his first interview since becoming president of the Royal College of Obstetricians and Gynaecologists. "Care overnight isn't as robust as it is at it is at 9am or 2pm. It's not as good. At 2am, you do not have the same experience."

Problems can arise because trainee obstetricians and other key staff, such as anaesthetists, who do almost all the night duty are much less experienced than those in the day. Junior obstetric doctors can lack the technical skills to use forceps or vacuum to ease a baby's birth, he said.

Disproportionate numbers of payouts by the NHS to settle cases of alleged medical negligence in childbirth involve babies born overnight, said Falconer, a consultant gynaecologist. Such settlements often reach £6m. The NHS should use most or all of the money spent settling such cases – around £300m a year – to hire 500 to 1,000 senior doctors, who would improve quality and safety of care by working round-the-clock in all big maternity hospitals, rather than just being available by phone to advise junior colleagues, he added.

"One of the ironies of the health service, and this view is shared by very senior people, is this culture that the NHS basically runs at one level for 40 hours a week, and at a completely different level for the rest of the week. And when you are dealing with acute services, that shouldn't happen," said Falconer.

Falconer stressed that most out-of-hours maternity care was perfectly safe, adding: "I don't want to frighten people and say that the quality of care at 2am is appalling, but it's not the same level.

"At night-time things go awry more often than they do in the daytime," he added. For example, trainee doctors working overnight may be too slow to realise that a new mother is still bleeding after a caesarean or to spot post-operative complications, he said. More senior doctors would mean "fewer mishaps".

Doctors, the National Childbirth Trust charity and patient safety experts said last night that they shared Falconer's concerns. "Tony Falconer is right. The NHS is a 9 to 5 organisation that bolts on the rest of the care it provides," said Belinda Phipps, the NCT's chief executive. "During 9 to 5 it's staffed better than any other time. So if you want to be sick or give birth, be sick or give birth between 9 and 5. Unfortunately most women give birth outside these hours."

Asked if the NHS had a two-tier maternity service, she said: "Yes. There's daytime care and there's out-of-hours care, and it's different. The out-of-hours care is inferior because you don't have everything, so if you need a consultant there and haven't got one, that's a problem."

"We know that junior doctors are often too quick to act inappropriately. They often take a medical route, such as using forceps or arranging a caesarean, because they don't have the confidence or knowledge to wait, because they can't tell the difference between a normal labour, where you should just sit and wait, and a complicated one which requires some intervention," she added.

Endorsing Falconer, Phipps said: "The NHS needs to ensure that it has someone of sufficient seniority available on the labour wards, not just on the phone. The benefits for women would be that appropriate action is taken. Consultants are often confident to do watchful waiting."

Lord Naren Patel, a retired obstetrician and until recently the chairman of the NHS's National Patient Safety Agency (NPSA), said: "There should be no inequality in the service. But there is inequality at the moment between the care during the day and at night. We need to ensure that obstetric care is delivered 24 hours a day by fully-trained, competent people – indeed any mother would want that. One hopes that this is the case and that, where it isn't, that's looked at urgently."

Dr Suzette Woodward, the NPSA's director of patient safety, said: "The care of all patients out of hours, overnight and at weekends, is a concern for those in patient safety, and if you ask any frontline doctor or nurse what keeps them awake at night they will often cite this as a key issue."

The numbers and grades of personnel on duty are a key factor associated with safety incidents out of hours, she said, along with tiredness and distractions.

Hospitals should do a daily assessment of the out-of-hours needs and ensure minimum staffing levels and that staff on duty have rapid access to those with high-level expertise, Woodward added.

But, she said, "I have no evidence that more c-sections are carried out because of the out-of-hours factors or that equipment is used inappropriately. Whether it be during the day or night, staff should only use equipment or carry out procedures for which they feel confident and trained in, and have the ability to say if they are not skilled or comfortable to do so," she said.

There should be no difference in the quality of NHS maternity care, the Department of Health insisted. "All mothers should expect consistently excellent maternity services, no matter what the time of day or night," said a spokeswoman. Proposed maternity networks are intended to give women high-quality services. "Local maternity services should ensure there are appropriate numbers of professional and support staff, and staffing levels should be reviewed and audited annually," she added.