Both the Conservatives and Labour have committed to keeping the triple lock.

It was temporarily suspended after the Covid pandemic distorted average wage figures, but later restored.

In the run-up to the General Election, the Conservatives have also promised to raise the tax-free state pension allowance in what they have called a “Triple Lock Plus”.

Under the plans, the personal allowance for pensioners would increase by at least 2.5%, or in line with the highest of earnings or inflation, meaning fewer would have to pay income tax on it.

A similar policy existed in the past but was scrapped by former Conservative chancellor George Osborne.

Labour has not set out whether it would make a similar move but said the Conservatives’ plan was not “credible”.

The proposed tax break for pensioners is “simply a reversal of a tax increase that the Conservatives proposed”, the Institute for Fiscal Studies director Paul Johnson has said.