It’s the Christmas dinner table accessory that children take most delight in.

But there’s one strange fact about the innocuous Christmas cracker that almost no one in Britain seems to realise: it’s illegal to sell them to anyone under 12.

Thanks to an EU directive, crackers are classified as low-grade fireworks and shopkeepers who sell them to children could be jailed for up to six months or fined £5,000.

Thanks to an EU directive, it is illegal to sell Christmas crackers to anyone aged under 12

The bizarre regulation has led to a number of cases of check-out staff challenging teenagers buying Christmas crackers.

Last week, a 16-year-old boy was turned away from a Sainsbury’s Local in Islington, North London, because he was unable to prove his age.

When the box of crackers he wanted was swiped through the till, the supermarket’s ‘Think 25’ warning flashed up on the screen, indicating that it was an age-limited purchase, like alcohol, cigarettes and adult DVDs.

The teenager had to leave the shop empty-handed, even though the minimum age at which they can be purchased was dropped last year from 16 to 12 in a Government crackdown on red tape.

A Sainsbury’s spokesman said: ‘Our corporate age restriction on Christmas crackers is 12, in line with trading standards policy.

‘But it is up to the discretion of store managers on whether to go ahead with a sale.’