A protester claims Chesterfield Library will not host an anti-EU rally for political reasons.
Labour Leave activist Gary Matthews said the library had agreed to hold the event on Monday but had now cancelled it.
Library bosses insist they do not have a record of a booking for Mr Matthews’ use of the lecture theatre.
Former MP and broadcaster George Galloway was among the speakers due to attend the rally.
Mr Galloway – who is leader of the Respect party and appeared on Celebrity Big Brother in 2006 – even tweeted a Derbyshire Times’ story about the event to his 250,000 followers.
Mr Matthews said: “I’m not happy about this at all.
“I feel like we’ve been banned from holding this event because Derbyshire County Council – which runs the library – is Labour-led and pro-EU.
“It’s going to be difficult to find another venue now. It’s very frustrating.”
But a county council spokesman said: “We’ve no record of a booking placed by Mr Matthews at Chesterfield Library for this date but we’re discussing this with him and are looking at the situation.”
Members of the public will go to the polls a week on Thursday in an historic referendum to decide whether Britain should leave or remain in the EU.
Anti-EU campaigners believe Britain is being held back by the organisation, which they say imposes too many rules on business and charges billions of pounds a year in membership fees for little in return. They also want Britain to take back full control of its borders.
Those campaigning for Britain to stay in the EU say it gets a big boost from membership – it makes selling things to other EU countries easier and, they argue, the flow of immigrants, most of whom are young and keen to work, fuels economic growth and helps pay for public services.