A human rights campaigner has been barred from speaking at Warwick University after organisers were told she was “highly inflammatory and could incite hatred”.

Maryam Namazie, an Iranian-born campaigner against religious laws, had been invited to speak to the Warwick Atheists, Secularists and Humanists Society next month. But the student union blocked the event, telling the society that Namazie’s appearance could violate its external speaker policy.

In an email to the society’s president, Benjamin David, a student union official said the decision had been taken “because after researching both her [Namazie] and her organisation, a number of flags have been raised”.

It went on: “We have a duty of care to conduct a risk assessment for each speaker who wishes to come to campus. There a number of articles written both by the speaker and by others about the speaker that indicate that she is highly inflammatory, and could incite hatred on campus.”

The student union’s policy says external speakers are “not permitted to encourage, glorify or promote any acts of terrorism” or “spread hatred and intolerance in the community” and “must seek to avoid insulting other faiths or groups”.

David said he felt embarrassed by the student union’s move and had lodged an appeal against the decision. “Maryam has always campaigned against violence and discrimination and has done so passionately for many years – something that should have been taken on board when the student union’s assessment was made,” he said.

Namazie said she hoped to go ahead with the event if Warwick changed its mind. “The student union seems to lack an understanding of the difference between criticising religion, an idea or a far-right political movement on the one hand and attacking and inciting hate against people on the other,” she wrote on her blog. “Inciting hatred is what the Islamists do; I and my organisation challenge them and defend the rights of ex-Muslims, Muslims and others to dissent.”

The student union said that as a charity it was required to conduct risk assessments of any external speakers proposed by its societies. “It is crucial to note, however, that the decision-making process is currently incomplete, and a final decision on this issue will be reached by the organisation’s most senior members of staff in the coming days,” it said in a statement.

“The initial decision was made in deference to the right of Muslim students not to feel intimidated or discriminated against on their university campus … rather than in the interests of suppressing free speech or freedom of expression.”

Namazie, who has written for the Guardian, is the spokesperson for One Law for All, a group that campaigns against sharia and religious laws, and a member of the Council of Ex-Muslims of Britain and the Worker-Communist party of Iran.

In 2005 she won the National Secularist Society’s prize for secularist of the year, presented by the Guardian columnist Polly Toynbee.

