The departing head of children's services in Norfolk has insisted she is leaving her post with her head held high, but that it was pressure from the county's MPs which led to her decision to quit.

Lisa Christensen, announced yesterday she would stand down as Norfolk County Council's director of children's services and take early retirement next month.

While she said she was leaving a department where improvements are being made - and one she is proud to have led - she acknowledged progress in some areas has not been fast or consistent enough.

Her departure comes after her department was blasted by Ofsted for the way it safeguards vulnerable children and for not intervening quickly enough in struggling schools.

The county's MPs last week issued a statement calling for an interim board to be brought in to take over the running of children's services - which amounted to a vote of no confidence in Ms Christensen.

The 56-year-old, who has worked at County Hall since 2002, is taking early retirement and will receive two months' gross salary in lieu of notice, which works out at £23,248.

The council will make a one-off compensatory payment to the Norfolk Pension Fund of £116,398. That money goes to the Norfolk Pension Fund rather than to Ms Christensen.

She said she hoped her departure would mean her 'talented and dedicated colleagues' could pull together to take the department forward, without the glare of potentially morale-sapping criticism in the media.

She said: 'Whatever I think of the fairness or unfairness of this, I hope me deciding it is time to go will lance the boil, as it were, and people will let the social workers, teachers and all the staff get on with what they need to be getting on with.

'There has been a lot of appreciation for what I have done, but when something happens like the MPs' statement, that puts the authority in a very difficult position.

'I think one of the things about being a leader means you have to show judgement about your own personal behaviour and position.

'I genuinely think that it is in the best interests of the authority and children's services, and myself, that I should go at this point.'

Despite her decision to go, Ms Christensen was adamant her department was moving in the right direction. She said the Ofsted criticism, while justified, did not tell the whole story of the 'exceptional work' being done in the department she has run since 2005.

She said Norfolk had outstanding residential homes and special schools, approaches to restorative justice which were being copied in other counties, an excellent youth offending team and an In Care Council which recently went to Westminster.

She said: 'The evidence is that the actual outcomes for our children and young people have improved and risks have lessened.

'But many challenges remain and in some key areas of this large and complex service, improvements have not been fast enough, or consistent enough. I know securing them is a firm priority for the council and all our partners.

'I hope that public support and recognition for frontline workers such as teachers and social workers, and those that provide support and leadership to them, will be to the fore in the coming months.' She added she believed 'constructive analysis based on facts' to be 'essential for healthy and accountable public services'.

She said: 'I hope my decision to leave the county council now, secure in the knowledge that it is in a good position to move forward positively, will enable my talented, and dedicated colleagues to move forward without the distraction of continued critical media attention which is in danger of sapping morale and compromising the very work we are engaged in.'

When asked what she thought of the statement the MPs had issued, she said: 'I cannot see that what they did will help with the job of improving things at the county council.'

But the MPs, who had called for a change of leadership, said they had acted in the best interests of the county's children.

Chloe Smith, Norwich North MP, said: 'I think this is the right thing to do. The Ofsted report found multiple inadequacies in what Norfolk Children's Services does for the most vulnerable children in the county.

'This saga is not political or sudden, it's too important for our constituents to have stayed quiet, and so we spoke out - having first raised our worries months ago.

'Leaders have to take responsibility and I hope this can be a fresh start now under new leadership.

'This is no comment on the many hardworking staff on the frontline, whose work I now hope can be boosted from the top.'

And Elizabeth Truss, South West Norfolk MP, said: 'I think it's the right decision. Norfolk MPs need to work with the county council in the future to ensure the best for our children.'

While James Joyce, children's services cabinet member for safeguarding at the county council, said Ms Christensen's decision to go was the right one, he branded the 'grandstanding' by MPs as 'unhelpful' and 'irresponsible'.

He said: 'I respect Lisa's decision and think it is the right one, especially in light of the very personalised attacks made on her of late, and for the service going forward.

'On behalf of the authority, I thank Lisa for her very hard work on behalf of all Norfolk's children and young people over the past eight years – a period during which we have seen improvements in many key areas of the services that she is responsible for.' He said the administration had made it a priority to deal with the problems and a robust improvement plan had been put in place.

Mr Joyce said: 'Norfolk's MPs were aware of this and that is why we felt their sudden grandstanding was not just unhelpful, but irresponsible.'

He said plans to recruit a 'top level interim director of children's services' were well underway and an announcement would be made shortly.

• The county council is also looking for a new head of finance. Paul Brittain, who has held the role since 2007, has announced he will retire at the age of 60 in September.

Council leader George Nobbs said: 'Paul is an outstanding public servant and his departure will be a loss to the council, making him a tough act to follow.

'He has successfully steered the finances of the council through the rockiest period for public financing anyone can remember and the latest audit report bears witness to just how successful this has been.'