Millions of children around the world face disappointment on Christmas Day as Santa Claus’ reindeer threaten to go on strike.

The reindeer are angry about changes to terms and conditions linked to a new pay deal and say that they will not fly over the Christmas period.

Donner and Blitzen both had serious safety concerns.

“We appreciate that it is a busy time of the year but the safety of our customers must come first.”

A spokesman for Santa Claus stated, “This calculated and heartless action is completely unnecessary and we are determined that it will fail.”

Rudolf, a red-nosed reindeer, was defiant in response.

“Our pay has been frozen for the last ten years and this is simply not acceptable.”