The NASUWT teachers' union will issue a legal challenge to the Government over its plans to reform public sector pensions.
The union, which is the largest representing teachers in the UK, argues that the Government should have valued the current Teachers' Pensions Scheme before making any changes.
The move will deal a blow to Government hopes that the matter was drawing to a close.
The NASUWT has set the wheels in motion for a judicial review by asking its solicitors to serve a pre-action notice on the Government's Actuary Department, the Secretary of State, and the Treasury. This is usually the first step before claiming judicial review in the courts.
The basis for the legal action is that the NASUWT contends that the Government has a statutory responsibility to conduct a valuation of the existing scheme prior to announcing any changes. The last valuation of the scheme was carried out in 2006 and the union states that regulations mean that further evaluation should be carried out during a period not exceeding five years.
"The Government has ignored our repeated requests to produce a valuation of the scheme," said Chris Keates, the General Secretary of the union.
"It is simply unacceptable and irresponsible for a Government to embark on changes which will have such a profound adverse impact on the financial future of teachers and their families without having evidence to demonstrate that a problem even exists," he added.
The NASUWT was one of a number of unions which lost a legal challenge to the Government's proposed change to the index pension system. An appeal on that challenge is due to be heard next week.
"Not only is the Government failing to meet its obligations to teachers, it is failing in its duty to act in the interests of the public. It is, however, probably safe to assume that if a valuation would have provided evidence to support the Government's changes it would have produced it," said Mr Keates.
The NASUWT has pledged to leave 'no stone unturned' in defending teachers' pensions.
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