An anti-racism rally will be held at Belfast City Hall this weekend in response to far-right demonstrations supporting English Defence League Tommy Robinson.
People Before Profit leader Gerry Carroll has appealed to "all progressives" in the city to join a protest on Saturday that coincides with a UK Freedom March, celebrating the anniversary of the EU referendum result.
It comes just two weeks after men were seen making Nazi salutes at a 'Free Tommy Robinson' rally in Belfast.
"I am calling on all progressives, all people with a sense of humanity, all people who abhor racism and can't stand the sight of bigots intimidating and bullying minorities in our city with their hate and lies," Mr Carroll said.
The West Belfast MLA has called on people to stand in solidarity with migrants - "especially Muslims" - as "organised groups of racists" take to the streets to "display their hate".
On June 9 hundreds of Tommy Robinson supporters turned out to protest against the convicted mortgage fraudster being jailed for contempt of court.
"These fascists claim to care about free speech and the plight of their dear leader," Mr Carroll said.
He branded Robinson as a "professional hate-monger" who has become a figurehead for groups like Generation Identity, which he said bears "all the hallmarks of white supremacy".
He also warned that "fascist" groups including Britain First were "desperate" to get a foothold here.
Mr Carroll described the "vile abuse" which a small number of United Against Racism protesters were subject to less than a fortnight ago as "stomach churning".
He claimed the "racist, sexist bile" was interspersed with "Nazi salutes from boneheaded thugs".
Councillor Jolene Bunting, who helped organise the Free Tommy Robinson protest, was later accused of "bringing Nazis to Belfast".
However last night, she condemned the salute.
"It was completely out of order, but it was taken out of context," she claimed.
"It was made in response to an insult in which the individual was called a Nazi."
She also shrugged off Mr Carroll's "astounding" criticism and accused him of having a short memory.
"These people are not fascists, racists or Nazis but fathers, mothers, daughters and sons who support freedom," she said.