Figures show that inflation is below target meaning that the basic state pension will be boosted by 2.5% next year.
The Triple Lock guarantee means that pensions will increase with inflation, earnings or 2.5 per cent - whichever is highest.
Commenting on the inflation figures, Liberal Democrat Chief Secretary to the Treasury,Danny Alexander said: "This below target inflation number is good news for everyone, but will help pensioners in particular as the Liberal Democrat flagship 'Triple Lock' policy will kick in to give an above inflation pension increase.
"The Triple Lock delivers a pension rise of whichever is the greater of average earnings, inflation or 2.5%.
"This means that next year the basic state pension will rise by 2.5% or £2.85 a week. With Liberal Democrats in Government the basic state pension has risen by over £950.
"This shows that pensioners are at the heart of our Liberal Democrat vision of a stronger economy and a fairer society.
"They've done their bit for society and paid their dues over a lifetime. Our Triple Lock policy ensures our country does right by them.
"This is in stark contrast to life under the Conservatives who broke the link between pensions and earnings in the Thatcher years, and life under Labour when pensioners were insulted with rises as low as 75p."