Almost a quarter of jobs in Redbridge’s child social services were unfilled before the coronavirus outbreak, with concerns the crisis could put vulnerable children at even greater risk.

Experts warn the nationwide lockdown could pile pressure on an already stretched system, with councils across England reporting high vacancy rates and reliance on expensive agency staff in their child protection operations.

New Department for Education figures show there were 48 full-time equivalent job vacancies in child and family social work in Redbridge in September – 24pc of a fully-staffed workforce.

Temporary agency staff, who can be far more expensive for councils than regular employees, were covering 20 of these vacancies.

Cllr Elaine Norman, Cabinet member for children and young people, said she is proud the council’s children’s social care services were rated outstanding by Ofsted last year but there remains challenges in recruiting permanently to social care vacancies.

She said: “Despite this challenge we continue to make every effort to fill vacant posts with permanent staff, and are steadily improving our caseload ratio.

“I have great admiration for the dedication of our teams and the progress we have made in children’s services.”

The Government has predicted that up to a fifth of the workforce across Britain could be off work at the peak of the coronavirus.

John McGowan, general secretary of the Social Workers Union, said social workers are already struggling with the effects of the outbreak, with many off sick or in self-isolation, meaning less qualified staff or unqualified assistants could be asked to perform statutory duties.

“There could be a real shortfall of qualified staff – it is happening already,” Mr McGowan said.

“Some councils have put an appeal out to people in management or who haven’t practised in a while to say ‘can you come back to the front line and fill the gaps?’”

Social workers in Redbridge had an average of 17.9 cases each in September.

The Department for Education says the emergency Coronavirus Act will help social workers continue their “vital role” supporting children and their families through uncertain times.

A spokeswoman said: “We are working urgently to address the additional challenges they face, including through our Act, which will reduce burdens on social workers and help others return to the profession.”

But the Social Workers Union says councils need an urgent cash injection for child services, as well as personal protective equipment to protect frontline workers while they carry out home visits.

Mr McGowan added: “Social workers have been lost in this equation. There’s a lot of support for NHS staff but few mentions of social workers who are out seven days a week helping vulnerable people.

“There needs to be an expression that social workers are a part of this too, that they are essential, and they need to feel valued.”