Republicans from across Britain are preparing for a historic protest against the monarchy, organised by campaign group Republic, at the Thames Diamond Jubilee Pageant on Sunday June 3.

Protesters will assemble near City Hall for what Republic has described as the “biggest republican protest in living memory”. Speakers including Independent columnist Joan Smith, human rights campaign Peter Tatchell, historian Ted Vallance and writer Owen Jones will address the crowd from 1:30pm.

The "loud, bold and provocative" demonstration will be in full view of the royal barge as the Queen and other royals disembark to watch the pageant pass through Tower Bridge. The pressure group has been in ongoing talks with the Metropolitan Police, who have pledged to facilitate the protest as part of their operations for the day.

Protest organisers have been buoyed by a recent ICM poll which found the number of people believing Britain would be worse off without the royal family has dropped sharply from 63% to 51% in jubilee year. This weakening of the monarchy's popularity has coincided with a surge of support for Republic, which has seen its supporter base grow by more than 100% in the last eighteen months, to over 21,000.

Earlier this month Republic published a new pamphlet - 60 Inglorious Years - which argues that the Queen’s reign has been characterised by “personal enrichment, feeble leadership and an obstinate refusal to allow real scrutiny of her role”.

Republic's chief executive Graham Smith said:

“Our loud, bold and provocative protest is a major step forward for the republican movement and an opportunity to kickstart a real debate about the future of the monarchy. The royals spend most of their lives shielded from criticism – this protest will give them a rare glimpse of the strength of republican sentiment in Britain today.”

“The hereditary system is offensive to all the democratic values this country has fought for in the past. The jubilee represents a celebration of everything we, as republicans, oppose – it is our right and duty to challenge it and promote the alternative.”

"The heightened Palace PR campaign of the last eighteen months has already backfired – people are sick and tired of being told they must celebrate 60 years of one very privileged, very remote and very uninspiring head of state. The idea that the monarchy's future is any safer as a result of the jubilee is completely laughable.”