The mother of a seven-week-old baby who died while in the care of out-of-hours GP service provider Harmoni joined campaigners to warn councillors further lives could be at serious risk unless the firm’s staffing problems are rectified by the peak winter period.

Linda Peanberg King, joined by members of Keep Our NHS Public (KONP), issued the warning to Camden councillors at a health scrutiny panel on Tuesday.

Campaigners submitted evidence which they claim shows Harmoni’s out-of-hours service has suffered long waiting times and a shortage of properly trained medical staff since the provider took over the contract in 2010.

Councillors on the panel said they would be pressuring the company’s bosses to provide assurances patients would not be left at risk as demands on the out-of-hours service increased over the Christmas period.

The council probe comes almost a year after the death of baby Axel Peanberg King.

He died at the Harmoni Centre at the Whittington Hospital when a cold which developed into pneumonia went untreated despite repeated visits to doctors employed by Harmoni.

A report by the Care Quality Commission (CQC) in March found Harmoni failed to reach national targets, including not having enough “qualified, skilled and experienced staff to meet people’s needs”.

The firm is said to have been trying to fill the gaps in staffing by sending GPs text messages asking for help and by offering them £1,350 to work just one shift.

The tactics have been described by campaigners as proof that the firm is “desperate” and that staffing problems may not be rectified in time for the peak winter period.

Camden KONP chairman Candy Udwin said: “If the out-of- hours service is failing it will have the knock-on effect of more people in need of urgent care turning up at hospital A&Es, and that could have a serious effect on the time it takes to be seen and get treated.”

Despite evidence submitted by the authors of the CQC report on Tuesday suggesting Harmoni was “making progress”, councillors said they hoped the panel’s findings would be used to determine how contracts are awarded in the future.

Cllr John Bryant, committee chairman, said: “I’ve always argued when handing out private contracts we should emphasise more on quality than on cost.”

As part of the panel’s investigation, councillors say they will also be looking at recent events in Hackney after GPs reclaimed control of the borough’s out-of-hours service from Harmoni.

David Tee, Harmoni’s regional director, said the CQC report found staffing was a “moderate not major concern” and that it “at no point suggested services were unsafe”.

He added: “We enter the autumn winter period with a strong, stable service underpinned by improved staffing levels and clinial oversight.”