Thousands of people could line the route to St George’s Chapel in Windsor Castle, where the royal couple are due to wed on May 19.
The protests, which have been organised on Facebook, have been set up in response to comments from a council boss who suggested police remove rough sleepers from the town for the big day.
Simon Dudley, Windsor Council’s Tory leader, controversially called on police to clear the town as he spoke of “an epidemic of rough sleeping and vagrancy” – although later insisted his comments had been aimed only at “commercial” beggars.
Now hard-left activists have been accused of plotting to disrupt the former Suits star and her royal beau’s wedding this Spring with a massive demonstration against the remarks.
Some even suggest turning up with sleeping bags and disguising themselves as homeless people, so police do not know who to “kick out”.
Yet although the rally claims to support rough sleepers, some of those organising or planning to attend the event have previously posted hate-filled comments about the royal family – including one that read: “F*** the Royals”.
Peter Mills, a left-wing blogger who frequently shares posts by the Momentum group, urged people on Facebook to “dress up as ‘homeless’ and line the Royal Wedding route”.
But a series of posts online revealed his anti-monarchy views- accusing the Royal family on “inbreeding” and bracing them “sub-average humans”.
He also shared a picture of Prince William and the Duchess of Cambridge holding hands with Prince George and Princess Charlotte alongside the message: “F*** them and their leech soap opera.’
And above a picture of the Queen, he wrote: “And this f****** leech can do one too.”
Speaking at his semi-detached home in Frome Mr Mills, 38, who writes for Left-wing blog Evolve Politics, admitted referring to the Royals as “leeches”.
But he said his words “just demonstrate the passion I feel about helping the vulnerable and highlighting the wealth disparity”.
He denied being a member of either the Labour Party or Momentum and insisted: “I have nothing against the Royal Family.”
A second protest organised on Facebook, called No Jacket Required, urged protesters to “dress down” for the event in “solidarity” with the homeless.
One protester wrote: “The idea is to dress down to the level of those that are obviously threadbare so that they cannot be distinguished from us.
“Thus making it very difficult to remove them/us… The cops will be wondering if they are harassing a homeless man, or whether it is one of the thousands of us.”
Mr Dudley’s remarks were branded “abhorrent” by local campaigners after he said there was “an epidemic of rough sleeping and vagrancy in Windsor” and called the police to focus on “dealing with this before the Royal Wedding”.
He said: “There is a growing concern amongst residents, businesses and visitors regarding the number of people occupying the streets of Windsor, who are begging during the day and in some cases taking occupancy throughout the night.
“In the Royal Borough we believe homelessness is completely unacceptable in a caring, compassionate community such as ours. We are working to create the necessary housing for our residents.
“Obviously, the level of tourist interest is set to multiply with the Royal Wedding in May 2018, and there are increased concerns from our residents about their safety. The whole situation also presents a beautiful town in a sadly unfavourable light.
“It’s largely vagrancy and begging… People marching tourists to cash points to withdraw cash, hanging out near car park ticket machines to get discounts and ask tourists for money’ during a lengthy discourse with residents.”