The Prime Minister is set to unveil a 'quadruple lock' on the state pension.
Rishi Sunak will announce plans to automatically raise the threshold at which pensioners start paying income tax to ensure that it stays ahead of the state pension today.
The proposals would save eight million pensioners £100 a year in tax from 2025 and almost £300 a year by the end of the decade, according to Downing Street.
"This bold action demonstrates we are on the side of pensioners," Mr Sunak said.
Quick to criticise Labour, he added: "The alternative is Labour dragging everyone in receipt of the full state pension into income tax for the first time in history."
Based on current forecasts - if the threshold stayed the same and state pension rose as expected - those in receipt of state pension would start paying income tax on it for the first ever time in 2027.
Annual payments are currently at £11,500, while the lowest band of income tax is set at £12,570.
Mel Stride, the Work and Pensions Secretary, said: "The last Labour government completely failed pensioners, with a £118billion pensions tax raid and an insulting 75% increase to the state pension.
"Sir Keir Starmer can pay lip service to supporting pensioners but we know it will always be the same old Labour, putting our pensioners at the back of the queue."
A 'desperate' plan
However, Labour has hit out at the Tories' plan, dismissing it as "desperate".
Jonathan Ashworth, the shadow paymaster general, said: "This is just another desperate move from a chaotic Tory party torching any remaining facade of its claims to economic credibility.
"Labour will protect the triple lock. But Rishi Sunak is planning to reward Britain’s pensioners for their loyalty by stabbing them in the back, just like he did to Boris Johnson and just like he has done to his own MPs."