Union protests at the government changing the way public sector pension increases are worked out have been thrown out by the High Court.
Several trade unions bought a joint case against the government for switching the official measure of inflation from RPI to CPI.
The unions claimed the decision meant lower pensions for public sector retirees and scuttled their financial plans for retirement.
The government argued the switch was fair and saved the country £6 billion a year.
The point at the centre of the row was the rate of increase between the consumer price index (CPI) and retail price index (RPI). Both measure inflation, but CPI strips out housing costs.
RPI typically runs at a higher rate than CPI, so switching between them results in lower index-linked pension increase for public servants.
The High Court judgment fell 2-1 in favour of the government, but leaves the decision open to appeal.
The unions had put figures before the court to show public workers would face a 15% decrease in pension payments and a lower tax-free lump sum payment than expected.
Lord Justice Elias said three of the four grounds of challenge were dismissed unanimously, while one was rejected by a 2-1 majority.
The switch to the CPI came into effect in April.
The government told the court that ministers were entitled to consider CPI “a more appropriate measure of changes in the general level of prices”.
TUC General Brendan Barber said: ‘This is a disappointing judgement for pensioners and scheme members whether they draw a private, public or state second pension.
“We take great heart that the court accepted the argument that the government did this to cut the deficit rather than carry out a proper consideration of the best way of measuring the cost of living for pensioners, even if only one judge said that it was unlawful.
“With the Office for Budget Responsibility now predicting that the long-term gap between CPI and RPI will be 1.4 per cent, pensioners in both private and public sector schemes will find that their pensions will be 20p in the pound lower after 18 years of retirement.”

