Maggie Atkinson has been appointed England's next Children's Commissioner after the Government rejected MPs' doubts about her suitability for the post.
Schools Secretary Ed Balls announced that he was pressing ahead with the move despite an unprecedented snub of his nomination by an influential committee.
A cross-party select committee had called on him to restart the selection process after being unconvinced by Ms Atkinson's suitability at a pre-appointment hearing.
The hearings were introduced on a trial basis last year to improve accountability in the appointment of a range of public figures, but until now no nominees had been snubbed.
The MPs said that, while highly experienced, she had failed to show sufficient "determination to assert the independence of the role, to challenge the status quo on children's behalf, and to stretch the remit of the post, in particular by championing children's rights".
They were roundly condemned by children's charities who said the judgment "beggared belief". And Mr Balls rejected the verdict, declaring that Ms Atkinson's evidence in fact showed she would be a "strong, effective and independent voice for the children and young people of our country".
In a letter to the Labour chairman of the committee Barry Sheerman, he said: "It is for these reasons that I have decided to appoint Maggie Atkinson to be the next Children's Commissioner for England and I am delighted that she has accepted that appointment."
Ms Atkinson, presently director of children's services in Gateshead and a former president of the Association of Directors of Children's Services, was picked from 40 applicants for the role by a "rigorous" selection process involving an independent panel of experts.
She will replace Professor Sir Al Aynsley-Green, whose five-year appointment as England's first Children's Commissioner finishes at the end of February.
Children's groups lined up to defend Ms Atkinson and express disbelief at the MPs' verdict. Barnardo's chief executive Martin Narey said he was "astonished" by the snub. Sir Paul Ennals, chief executive of the National Children's Bureau (NCB), said: "Everyone who knows Maggie knows of her robustness, her independence of mind, and her strength of character."
The committee's report, which was agreed without a vote, concluded: "While we are satisfied that Maggie Atkinson demonstrated a high degree of professional competence, we feel unable to endorse her appointment, as we would like to have seen more sign of determination to assert the independence of the role, to challenge the status quo on children's behalf, and to stretch the remit of the post, in particular by championing children's rights."
In his letter, Mr Balls said the new scrutiny process required him to take into account any "new, relevant facts about the candidate's suitability" revealed by the MPs and in "exceptional" cases their performance in front of the select committee.
He welcomed the committee's recognition of the candidate's "high degree of professional competence" but went on: "On the basis of all the evidence before me and, indeed, before the committee, I would go considerably further.
"In my view, her career history...provides ample evidence that Maggie Atkinson is one of the most outstanding directors of children's services (DCSs) in this country, and is thus an excellent candidate for the post of Children's Commissioner."
He concluded: "My duty is to appoint the best person to this important job.
"Having considered your report, I have concluded that it does not put forward new relevant facts concerning Maggie Atkinson's suitability for the post such as to cause me to alter my nomination of her to the post of Children's Commissioner, thereby rejecting the recommendation of the independent panel established as part of the standard Nolan recruitment process.
"Nor do I consider that her performance at the hearing comes into the 'exceptional' category set out in the guidance. On the contrary, the transcript of the hearing leads me to the view that Maggie Atkinson gave robust and intelligent responses to the questions put to her, and in so doing further demonstrated her suitability for the role.
"I continue to have every confidence that Maggie Atkinson's professional and personal credentials will ensure that as Children's Commissioner she will be a strong, effective and independent voice for the children and young people of our country, which is what they need and deserve."
Committee chairman Barry Sheerman branded Mr Balls a "bully" who always wanted his own way, and said that his decision to override the committee's rejection of Ms Atkinson was "a bad day for parliamentary democracy".
Mr Sheerman said that the schools secretary did not like holders of influential posts in the education system who would stand up to him, citing the cases of Ken Boston, who resigned as head of the Qualifications and Curriculum Authority (QCA) after being blamed for the chaotic marking of Sats exams, and academy schools champion Sir Bruce Liddington, who quit as schools commissioner last year.
"Maggie Atkinson is a very competent woman but we just didn't think whe had the independence of mind to stand up to a secretary of state who likes to get his own way," Mr Sheerman told BBC Radio 4's Today programme.
"Most of us know that Ed Balls is a bit of a bully and he likes his own way and we have seen a track record of problems over Ken Boston at the QCA and Bruce Liddington the schools commissioner, who was very independent - he has gone and the school commissioner has been abolished.
"Time after time, we see the secretary of state wanting to have people who will do his bidding.
"He is more of an executive man, rather than a parliamentary man, and I think it is a bad day for parliamentary democracy when - if we are having these pre-appointment hearings - the very first one to say it didn't agree with the appointment gets overridden."
Mr Sheerman is considering standing for election as chairman of the Parliamentary Labour Party, but dismissed suggestions that his action was designed to convince the party's backbenchers that he was himself able to stand up to senior ministers.
The decision to turn down Ms Atkinson was taken unanimously without a vote by all eight committee members from all three major parties, he said.
"We thought that someone who was keener on the campaigning role, someone who was feistier in standing up to the secretary of state (was needed)," he said.
"He does have form in this area. Ofsted is at its weakest that I have known under six secretaries of state. He doesn't like strong independent-minded people who stand up to him and that's why Sir Bruce Liddington went, that's why we had all the problems with Ken Boston at the QCA last year. There is a history and we at the select committee see the pattern."
No 10 said that Gordon Brown endorsed Mr Balls' decision to go ahead with the appointment.
"The Prime Minister supports the decision the Secretary of State has made," Mr Brown's spokesman said. "I think the system is working. The system is an advisory one."
Director of campaigning group Unlock Democracy Peter Facey said: "This is the first real test of the confirmation system which has been introduced to enable select committees to scrutinise ministerial appointments. The indications are that it has failed badly.
"Regardless of Maggie Atkinson's suitability for the post of children's commissioner, if a select committee has rejected her, the secretary of state should not simply be able to dismiss their conclusions out of hand.
"At a time when government itself is arguing that parliament should be given greater scrutiny powers, this shows quite how powerful the executive is in the face of a supine parliament.
"We need a written constitution to precisely define and limit the powers of government."
Shadow children's secretary Michael Gove said: "Ed Balls seems more interested in getting in his own person to this role than hiring the individual who might be best for the job.
"Ed's candidate failed to convince this group of mainly Labour MPs that she was strong enough to stand up to him, and now he's being accused of bullying.
"Rather than go ahead in such a partisan way, the Secretary of State should think again so that he gets the best person for the job and someone whose independence from ministers is not compromised."
An urgent question will be posed in the Commons at 3.30pm today asking Mr Balls to make a statement on the appointment of the commissioner, parliamentary officials said.