A leading universities body has withdrawn guidance on the gender segregation of audiences in lectures and debates, after Prime Minister David Cameron said it should not be allowed to happen.
Universities UK said a controversial case study setting out the guidance was being withdrawn while it reviews its stance, but insisted that the legal position remains "unclear" on whether the voluntary separation of men and women could be allowed at events such as lectures on Islam by visiting speakers.
However, the Equality and Human Rights Commission said that, while the law allows segregation by gender in premises being used for religious purposes, it was "not permissible" in an academic meeting or in a lecture open to the public.
UUK, which represents higher education institutions across the country, has requested help from the EHRC in establishing clarity about the legal position, after the guidance it published last month sparked protests from students and outrage from some politicians.
Education Secretary Michael Gove said: "We should not pander to extremism. Speakers who insist on segregating audiences should not be indulged by educators.
"This guidance is wrong and harmful. Universities UK should withdraw it immediately."
And Mr Cameron's official spokesman told a daily Westminster media briefing the Prime Minister felt "very strongly" about the issue and believed it raised "an important issue of principle".
"He does not believe that guest speakers should be allowed to address segregated audiences, so he believes that Universities UK should urgently review its guidance," said the spokesman.
He stressed that the PM's comments did not relate to religious services in places of worship or on university premises: "There is a distinction here between how individuals choose to practise their faith and requests that speakers may make when they come to give a talk at a university."
But he said that the PM did not believe segregation by gender should be allowed in lectures and debates, even if it is voluntary.
Asked if Mr Cameron was ready to legislate to stop segregated audiences on campus, the spokesman said: "We want to support universities in taking a tough approach, and if more may need to be done then of course the Government would look at that."
Nicola Dandridge, Chief Executive of Universities UK, said: "Universities UK agrees entirely with the Prime Minister that universities should not enforce gender segregation on audiences at the request of guest speakers. However, where the gender segregation is voluntary, the law is unclear. We are working with our lawyers and the EHRC to clarify the position.
"Meanwhile the case study which triggered this debate has been withdrawn pending this review."
UUK's guidance set out hypothetical case studies which come up on campuses, including whether a speaker from an ultra-orthodox religious group requests that an audience is segregated by gender. It set out the legal framework which universities should bear in mind when making their own decisions on what action to take.
The report stated that university officials must consider both freedom of speech obligations and discrimination and equality laws. And it concluded that institutions ought not to enforce segregation, but if participants were happy to sit in separate groups that should be permitted as long as no disadvantage was caused.
Shortly before the withdrawal of the guidance, a Universities UK spokesman said that advice from senior legal counsel had confirmed that it was "correct and provides an appropriate foundation for lawful decision-making", but said that the organisation was working with the EHRC to ensure that it was "consistent and clear for universities".
"For the avoidance of any doubt, we are not talking here about enforced segregation. It is very hard to see any university agreeing to a request for segregation that was not voluntary and did not have the broad support of those attending," said the spokesman.
But ECHR chief executive Mark Hammond said it was not "permissible" under the law for universities to segregate by gender in academic meetings.
"Clearly a university like any other institution is entitled to provide services and facilities separately by gender where appropriate and lawful - for example, accommodation, sports and targeted welfare provision," said Mr Hammond. "It is also entirely permissible for a university or other organisation to have private members clubs for a single sex.
"Universities can also provide facilities for religious meetings and associations based on faith, as in the rest of society. Equality law permits gender segregation in premises that are permanently or temporarily being used for the purposes of an organised religion where its doctrines require it.
"However, in an academic meeting or in a lecture open to the public it is not, in the commission's view, permissible to segregate by gender."
Mr Hammond added: "The UUK's guidance accepts that the initial question is whether that segregation is discriminatory and concludes that the imposition of segregated seating in certain circumstances could be permissible. The guidance also gives the impression that the right to manifest or express a religious belief should be balanced against the right not to be discriminated against.
"We think the guidance could be clearer on what the legal framework lays down on these issues to avoid any risk of misrepresenting the legal position. UUK has now written to the commission and we have agreed that we will work with UUK to ensure that their guidance and our guidance are consistent and clear."
Tahir Nasser, chairman of the Ahmadiyya Muslim Students' Association UK, which regularly organises lectures about Islam on university campuses, said: ''I completely disagree with the forced segregation of students at universities.
"However, this is really a non-issue as Muslim women and men who feel more comfortable sitting next to people of the same gender are already able to do so. Their personal preference should not be imposed upon others who have a different preference.
"However, at the same time, those wishing to freely sit separately should be able to do so and their rights respected just as those of others are.''