Another senior officer in Norfolk County Council's troubled children's services department has made a sudden exit.

Lesley Whitney, one of the assistant directors in the department, which has endured recent criticism from watchdogs, left County Hall for the last time yesterday.

Sheila Lock, interim director of children's services, broke the news of Mrs Whitney's departure to staff in an email on Wednesday.

Staff were told that Mrs Whitney, 58, would be taking early retirement from October, but because of her leave entitlement, yesterday was her last day.

Mrs Whitney's departure follows that of her former boss Lisa Christensen. The former director of children's services announced in June that she was taking early retirement.

Her departure came after inspectors from Ofsted criticised the way the council looks after vulnerable children and the support it gives to schools, which led to the county's MPs to call for a change in leadership.

Mrs Whitney, has worked at the council for 18 years in two stints, from 1986 to 1997 and from 2006. Most recently she was assistant director for early help.

She had been responsible for leading a wide range of services for vulnerable children and young people, including the safeguarding and looked after children fieldwork teams, services for children with disabilities, residential care, adoption and fostering, plus special educational needs.

She said: 'It has been a privilege to experience first hand the dedication of frontline staff and those that support them.

'I leave at a time when there are significant challenges in children's services and I wish all of my colleagues well in continuing to drive forward the improvements that are needed.'

Meanwhile two new members of staff have joined – Andrew Haley, as head of safeguarding and Helen Wetherall, interim assistant director for improvement.

Mrs Lock said: 'Lesley has made a huge commitment to children's services both here and in other areas of the country and I wish her a happy and healthy retirement. I will be taking steps in the next week or so to secure additional support and leadership.'

The county council announced last month it would be spending an extra £16.5m for more social workers, school improvement advisers and children with special educational needs.

But the authority is also consulting on £140m of cuts over the next three years, with proposals looking to save millions of pounds.

Some £17.6m of those cuts are by changing services for young people, with the authority looking to dramatically cut the number of young people who end up in care.