The move is expected to save the Treasury £350m in 2010/11 compared to if the rise had applied to all parts of the state pension.
In his pre-Budget report last week, Darling said the “basic state pension will not be frozen, but will rise by 2.5 per cent in April”.
The report did not mention that the parts of the state pension which do not count as basic would be frozen.
Pensions minister Angela Eagle told the BBC over the weekend that extras such as the state earnings related pension will be frozen adding that this will prevent unfairness between Serps and company pension schemes.
But shadow chief secretary to the Treasury Philip Hammond says: “As always with this Government the headlines of their announcement unravel when we see the small print.
“The pensions minister has revealed Alistair Darling’s 2.5 per cent rise will not actually apply to all pensioners.
“This year’s PBR has been the most political and cynical of Labour’s term in office, now we see the cruel deceit of pensioner and benefit recipients who were given false hope on Wednesday, only to have their expectations dashed by Saturday.”