Campaigners have called on Kensington Palace to explain the photo of Kate Middleton and her children which has been withdrawn by press agencies on suspicion of it being manipulated.

The nature of the manipulation of the image raises serious questions, such as why they thought this was necessary, and what was the original photo that has been doctored?

Speaking for Republic, Graham Smith said today:

"If the palace can't offer a simple, innocent explanation then 'Kategate' is going to cause the monarchy serious damage."

"The manipulation of an image that the palace says was taken by William is extraordinary. If true it is a deliberate attempt to deceive the public."

"This kind of dystopian behaviour you might expect from Soviet Russia, not modern Britain. The monarchy has always sought to manipulate and manage its image, but if they have tried to fake a photograph to silence online conspiracy theories, that is disgraceful."

"For Kensington Palace to simply decline to comment is unacceptable. The royals are funded by the taxpayer, William thinks he's entitled to be our next head of state. So the public are entitled to know what's going on."

"The obvious question is why? What is going on that made them feel it was necessary to issue a manipulated image? Was Kate in that photo at all?"

"This could cause the monarchy serious damage. A poll out this week shows more people under 45 want a republic than a monarchy. Support across the country has been falling. To damage any trust the royals may still enjoy is going to weaken their support event further.

"Again we are all reminded of the shortcomings of this strange and archaic institution - and why we need a serious and honest debate about abolishing the monarchy."

Republic will be protesting at the Commonwealth Service in Westminster on Monday from midday.

Polling from this week is here.