Further analysis from the Institute for Fiscal Studies (IFS) suggests the proposed changes could significantly reduce Government spending on pensions.
The think tank estimates that if Mr Burnham’s double lock had been in place since 2011, annual State Pension spending would now be £9billion lower.
However, pensions would still have increased by around 75 per cent over that period, representing a real-terms rise of approximately 6 per cent.
Jonathan Cribb, deputy director at the IFS, said: “For pensioners, the reform means that state pensions will still rise in real terms over time but more slowly than under the current system, and in the long run their pensions will keep pace with growth in employees’ average earnings.”
Mr Tronson warned that removing the earnings element could make it harder for future retirees to rely on the State Pension alone.
He highlighted that earnings growth has determined most annual State Pension increases since the triple lock began, including two of the three largest uplifts.
Among these was the 8.5 per cent increase in 2024.
Mr Tronson said: “Moving to a double lock will make it even more important for those still in work to start building their own retirement savings early, whether through a workplace pension or self invested personal pension (SIPP), rather than relying on the State Pension alone.”
A DWP spokesman said: “This settlement is a better deal for pensioners and their families and ensure the state pension system rises every single year by at least the highest of 2.5%, CPI inflation or a new earnings link.
“We are committed to the triple lock for the rest of this parliament, which will see the new state pension rise by over £2,000 and reach a forecasted record high by April 2029. The adjusted triple lock will build on the gains the policy has made for pensioners.”