The website of a Labour Party branch based in Bristol has been taken over by an activist who has launched an astonishing attack on Jeremy Corbyn, his allies, and the left-wing grassroots organisation Momentum.

The Labour Bristol site was edited by Lyle Hopkins, who claims on the webpage to expose the "truth" about Corbyn and Momentum. Hopkins advocates Saving Labour — the group campaigning for Corbyn to be replaced by Owen Smith in the upcoming leadership contest.

The updated site accuses Corbyn of deception for posing as a champion of the working-class even though he attended private school as a child and grew up in a "manor" during his youth. Hopkins also accuses the current Labour leader of being a "career politician" and "ill-equipped" to lead both the party and the nation.

You can read the website's claims about Corbyn below.

Hopkins, who is a Labour Party member, also makes some accusations regarding the behaviour and practices of the Momentum grassroots movement (see below). Momentum was set up to support Corbyn as he rose to the top of the party last year.

He claims Momentum is an "unaccountable" and "undemocratic" collection of private companies owned by pro-Corbyn activist John Lansman, which isn't transparent about where membership money goes. It also accuses the organisation of breaching Data Protection law by harvesting peoples' personal information.

The site also called Momentum national organiser James Schneider and Lansman out for being "elitists from privileged backgrounds" who are falsely portraying themselves as "anti-establishment" voices.

A line of text at the bottom of the page clarifies that the website domain was formerly loaned to the official Bristol Labour branch, but now Lyle, as its owner, is using it to publicise an anti-Corbyn agenda.

"The domain (labourbristol.org.uk) was being loaned to the Bristol Labour party. Repeated efforts to get them to take ownership of the domain failed. With the current situation, I am no longer inclined to keep loaning it to them. I will likely re-purpose this domain for Bristol based Labourers information."

Business Insider spoke to Lyle on Tuesday afternoon to find out why he gave the site the makeover.

"I think the final straw was the toxic Bristol West meeting," he told us. "Seeing how unpleasant, threatening and intimidating so many of the Corbyn supporters were, and then how they set upon anyone on social media that dared to stand up and be honest about the meeting."

Business Insider contacted Momentum and Jeremy Corbyn's office for comment but both declined. Saving Labour and John Lansman were not immediately available for comment.