Cadbury's parent company Mondelez blamed rising inflation in the production of its chocolate as it reduced the size of its larger bars from 200g to 180g.
The bars will still typically be sold at £2 despite the size reduction.
US parent company Mondelez said the shrinkflation – reducing the size of a product but keeping its price the same to improve profitability – was the first by Dairy Milk in a decade.
In 2012, a 49g bar was reduced to 45g but the price remained 59p.
A year earlier the 140g chocolate bar was reduced in size to 120g.
Rishi Sunak is having to face up to the cost of living crisis
UK Parliament/Jessica Taylor
It comes as the cost of living crisis gathers pace, with accelerating food inflation placing pressure on UK households.
Last week, Consumer Price Index (CPI) inflation struck a new 30-year-high of 6.2 percent for February and is expected to soar beyond eight percent in the coming months.
The figures for February showed that food inflation increased by 5.3 percent year-on-year, with milk, fresh meat and coffee reporting particular sharp increases.
A Mondelez spokesman said: “We’re facing the same challenges that so many other food companies have already reported when it comes to significantly increased production costs – whether it’s ingredients, energy or packaging – and rising inflation.
“This means that our products are much more expensive to make.
“We understand that consumers are faced with rising costs too, which is why we look to absorb costs wherever we can, but, in this difficult environment, we’ve had to make the decision to slightly reduce the weight of our medium Cadbury Dairy Milk bars for the first time since 2012, so that we can keep them competitive and ensure the great taste and quality our fans enjoy.”
Dairy Milk bar
PA Features Archive/Press Association Images
