The Retail Price Index, used in pay negotiations, now stands at 4.4 per cent, way above the salary increases of 2.5 per cent fixed for September 2006 and 2007.
Steve Sinnott, general secretary of the National Union of Teachers said increased inflation would amount to a pay cut for teachers if nothing is done.
A special clause in the wage agreement allows for unions to request a review of pay if average headline inflation rises above 3.25 per cent for the financial year.
Financial experts have confirmed that this is highly likely to happen.
A 1 per cent pay rise across England and Wales would mean a cost to the teachers' paybill of around pound;200 million, although the NUT has not yet specified the level of the rise it would ask for.
Mr Sinnott has written to the School Teachers' Review Body, which advises the Government on pay, requesting a review.
He said in the letter: "Indepen-dent forecasters predict that headline inflation will be around 4 per cent in the first quarter of 2007. The 2.5 per cent increase received by teachers on September 1, 2006 and the levels of headline inflation have therefore resulted in a real cut in teachers'
pay which should be remedied without delay."
He told The TES: "Teachers are already way down the range of pay for qualified people, so this will cut things back even further."
A spokesman for the NASUWT union said it would also be urging a review if the average rate of inflation for the year was above 3.25 per cent.
Mary Bousted, general secretary of the Association of Teachers and Lecturers, said if the level of 3.25 per cent was reached, the issue of pay must be looked at.
Andy Inett, head of negotiations at the Local Government Associ-ation, said: "We don't antici-pate any review of pay until later this year. Any increase will obviously have an impact on employers and we would expect support from central government."