NHS campaigners have hit out at a major private healthcare provider that faces a litany of allegations – as the company is set to be hauled over the coals by health chiefs in north London.

Senior doctors have alleged that private equity company Harmoni, which runs out-of-hours GP services in Islington and four other boroughs, has not met demand for doctors and nurses, putting patients’ lives at risk.

When Fred Kavalier, former lead clinician of Harmoni, resigned in 2011 he wrote a letter to directors highlighting his “urgent concern about the quality and safety of the service Harmoni is providing in north central London”.

He added that there were not enough doctors to fill shifts and the length of appointments had been cut.

Now Harmoni may be held to account next month by all five boroughs that are part of NHS North Central London, the body that runs health services.

Cllr Martin Klute, who represents St Peter’s ward, has asked the company to attend the next meeting of the watchdog health scrutiny committee, as has Cllr David Winskill from Crouch End in Haringey.

Cllr Winskill said: “We are going to ask how long they are taking to answer the phone, the type of advice they are giving and whether they have adequate staff.

“We’re also concerned that they’ve reduced the amount of time GPs can spend with patients.”

Harmoni “categorically refutes” that its out-of-hours services have been or are currently short-staffed or that its service is unsafe.

An NHS North Central London spokesman said: “The successful bidder [Harmoni] demonstrated during the tendering process [for the out-of-hours contract] that they can provide a high quality service within the financial envelope we have available to us.”