They are a family favourite – a staple of the British sweet counter and the Christmas stocking.

But after decades of satisfying the country’s sweet tooth Terry’s Chocolate Orange has been hit by claims it has been ruined by its new American owners.

The treat, first manufactured in York in 1932, has been reduced from 175g to 157g in weight – a cut of 10 per cent - prompting outrage among its fans.

They say the famous chocolate segments have been reduced in size by Cadbury, which is now owned by the US giant Mondelez International.

Aficionados of the orange flavoured confectionary have set up a Facebook page bemoaning its reduced weight.