McVitie's are shrinking their biscuit packets because of '˜rising costs'

The 500g packet of 34 biscuits will go down to 400g and will be on supermarket shelves from 22 January.

The product will have a recommended retail price (RRP) of £1.15 – 10 pence cheaper than the RRP for the 500g packet – but it is ultimately up to retailers to set the price.

The change is down to higher ingredient costs, according to McVitie’s owners Paladis.

Paladis UK and Ireland managing director Nick Bunker said: ‘The rising cost of ingredients and changes in the exchange rates means it has become more expensive to bake our products.

‘We work hard to drive efficiencies throughout our business to absorb cost increases, but occasionally, like many other businesses in these challenging times, we do need to make some adjustments.

We work hard to drive efficiencies throughout our business to absorb cost increases, but occasionally, like many other businesses in these challenging times, we do need to make some adjustments.’

According to the Office for National Statistics, more than 2,500 products have shrunk in size over the past five years.

In 2016 the shape of Toblerone was controversially changed to cut the bar by 40g – with no change in price.

This story originally appeared in our sister paper, The i.