EU referendum: Palace voices 'regal displeasure' over Brexit claims
It is unusual for the Queen to take action against a newspaper.
It is a sign of the depth of regal displeasure.
It's the Sun headline, "Queen Backs Brexit" which is both toxic and very troubling to an institution which prides itself on remaining above the political fray.
But the course of action the palace has now embarked upon brings with it risks. It's a far cry from the "never complain, never explain" mantra once deployed by officials in the past.
The letter to the press watchdog ensures that the Sun story continues to be debated.
And there continues to be a focus on what the Queen chose very deliberately to do four days before the Scottish referendum.
When she told a well-wisher in 2014 "I hope people will think very carefully about the future", it was interpreted as support for Scotland remaining within the UK.
It was a planned remark the Queen and her senior advisers may come to regret.