Protesters planning action outside Scientology’s UK HQ during its ‘greatest gathering’

Protesters are planning the largest UK demonstration against Scientology for 15 years, outside what the controversial organisation is calling its “greatest gathering”.

The Scientology leader, David Miscavige, who has been served with lawsuits in the US, including for human trafficking, which he denies, is expected to fly in for the event at the former home of the religion’s late founder, L Ron Hubbard, in East Grinstead, West Sussex, from 3 to 5 November.

The International Association of Scientologists says attenders will “hear about our recent victories, pivotal milestones and upcoming expansion plans” as well as the “heroic things we do for humanity every day”.

The organisation, whose celebrity followers include Tom Cruise and John Travolta, has long been controversial because of claims that it separates its members from their families and indoctrinates followers.

The peaceful protest has been organised by Alexander Barnes-Ross, who says he joined the Scientologists aged 15 in 2011, became its director of public book sales in London in 2013 and was kicked out in 2014.

He said the protest was “sending Scientology a clear message: the abuse must stop”, and was expected to be the largest in the UK since a 2008 demonstration by members of the internet-based group Anonymous outside the church’s London HQ, which attracted more than 300 people.

Barnes-Ross believes people have been galvanised by ex-members such as himself speaking out on social media and recent controversies relating to the church.

In April, a Florida judge ruled that the human trafficking allegation against Miscavige must be decided by an arbitration panel of loyal church members and not a court as the three accusers had previously signed agreements to resolve any future dispute through this route.

Miscavige has also been named in a lawsuit, filed by the actor and former Scientologist Leah Remini against the church and its leader, alleging harassment, defamation, surveillance and other unlawful behaviour resulting in “psychological torture”.

Last year, the actor Danny Masterson, who starred in That 70s Show, was sentenced to 30 years to life in prison for raping two women two decades ago after a trial in which prosecutors argued that the prominent Scientologist had used his role in the church to avoid accountability for the attacks.

Two accusers, former members themselves, alleged the church had discouraged them from contacting law enforcement for years. This was denied by Scientology.

Scientology told the Guardian the UK protest was harassment “orchestrated by an anti-Scientologist who exploits his few weeks of participation in the church over a decade ago”. It said allegations against the group were “totally false” and that the Florida human trafficking case and the lawsuit brought by Remini were “blatant harassment”.