Police in Cambridge have deployed more than 670 officers as the English Defence League and anti-fascist groups march through the city.
Cambridgeshire Police expect up to 500 members of the EDL to take part in a march.
Similar numbers from Unite Against Fascism and the TUC will take part in a counter march.
East of England MEP Richard Howitt will deliver a speech to the counter march. He will say: "We publicly attest that the EDL is not welcome in this city because we cannot let the poison of their ideas seep in to the body of our community.
"I am proud to live and work in this, the most international of cities, where one in 10 of my neighbours comes from black or ethnic minority communities.
"This is a city which spoke out to end slavery 50 years before it was abolished and today, over two hundred years later, we speak out to restate that there can never be those amongst us who can be treated as less than equal."
Mark Woods, speaking on behalf of Cambridge's Muslim community, said: "We accept that there's a right to free speech but there are also laws against inciting racial hatred.
"The Muslim community here recognises it has had its own problems and is working hard to tackle those.
"Our message to the EDL is: you're not welcome in Cambridge."