The King sought to portray a message of unity at today’s Commonwealth Day Service, as he was joined by his son and heir and his stoic sister for the staple royal event.

What the King didn’t pay attention to was the large group of anti-monarchy protestors chanting across the street. The group of flag-waving Republicans shouted “what did you know” as they wielded banners with photos of his disgraced brother, Andrew Mountbatten-Windsor.

The heckling was largely drowned out by the Abbey bells and musicians but there was no escaping the bright yellow banners and flags just yards away.

Seeing the senior royals drive past the anti-monarchists, who were asking questions about the Andrew scandal, was a stark reminder of the crisis afflicting the crown.

While the King has sought to distance himself from his brother by stripping him of his titles, banishing him to the private Sandringham Estate and releasing carefully worded statements, the police investigation is ongoing.

And public anger continues to mount, with a growing movement of politicians and activists calling for Andrew to be axed from the line of succession.

This week, the King is expected to discuss the matter with Commonwealth leaders, as removing him as a successor requires each Realm to introduce its own legislation.

It is understood that Commonwealth nations agree that he should be removed as the eighth in line to the throne.

But the King sought to keep the focus firmly on celebrating the family of nations today, rather than the problems his own family faces.

It marked an important moment for the Firm, as the King, Queen and the Prince and Princess of Wales united in public since Andrew’s arrest last month.

There is no doubt that the show of unity came at a crucial point, but the prevalence of the protestors proves that the questions surrounding the former Duke of York are not going away anytime soon.