Republicans from across Britain are heading towards central London today (29 April) for Republic's "Not the royal wedding" street party.
The party, billed a "celebration of democracy and people-power rather than inherited privilege", is expected to attract hundreds of republicans to Red Lion Square in the midst of the capital.
Though the established Church of England is playing a central part in the royal wedding, Christians will be among those taking part in the alternative celebrations.
John Bryant told the Republic website: "Monarchy is just plain wrong: possession of power just because of the family into which one is born offends against natural justice and against my Christian values."
Party-goers will enjoy food, music and republican-themed stalls and games. Republic has described its royal wedding plans as a "a genuinely historic moment for republicanism".
The pressure group has seized on the latest YouGov poll which revealed a majority of Britons are not interested in the wedding and believe there has been too much media coverage of the event.
Republic campaign manager Graham Smith explained: "This is the first time that republicans have staged their own campaign events at the time of a major royal occasion, so it's a genuinely historic moment for republicanism."
He added: "Tomorrow is the culmination of the most successful period for our campaign since we became a pressure group five years ago. We're looking forward to even more intensive campaigning as we prepare for jubilee year and work towards getting rid of the monarchy altogether by 2025."
"In a last ditch attempt to whip up enthusiasm for the wedding, the palace is relying more and more on spin and half-truths. Poll after poll has shown that most Brits simply don't care about the wedding and feel the media has badly misjudged the mood of the nation," said Smith.
"The idea that the monarchy's future is any safer as a result of the wedding is completely laughable. The startling fact is that despite the relentless hype, support for a republic has actually increased in the last few months," he concluded.
More about Republic: http://www.republic.org.uk/