The increasing tendency for people to define themselves by their faith, gender, sexuality or race is undermining empathy among Britons, says the chair of the country’s equality watchdog.

David Isaac, chair of the Equality and Human Rights Commission, told the Observer that identity politics had been hugely important in advancing the civil rights of many groups. But he warned of a danger that “individual interests” were narrowing people’s views and diminishing their connection to wider society.

Speaking amid an intensifying row in Birmingham, where a group of predominantly Muslim parents have staged protests outside schools accused of promoting same-sex relationships, he suggested the commission would be prepared to use its legal powers to protect the teaching of LGBT issues in the face of opposition from faith groups. “We are a strategic regulator,” Isaac said. “We can’t support absolutely everybody, but we will take cases where we thinks it moves the law forward to protect human rights.”

Recently the commission has become more vigorous in using its legal powers against groups it believes threaten equality.

“We are about to make a decision whether to investigate antisemitism in the Labour party, and that’s a good example of where, without fear or favour, we are saying in relation to political parties, whether it is Islamophobia in the Tory party or whatever, that if we find unlawful acts we are prepared to use our powers to do something about it,” Isaac said.

Facebook Twitter Pinterest David Isaac, chair of the Equality and Human Rights Commission. Photograph: Sarah Lee/The Observer

On Friday, Birmingham city council took the decision to close Anderton Park primary school, where parents have been protesting for seven weeks, early for the half term. The MP for Birmingham Yardley, Jess Phillips, has attacked the decision, which she said was down to “bullies and bigots” and contrary to the Equality Act.

“Everything that is happening at the Anderton school in Birmingham is probably making some headteachers nervous about their commitment to teaching about minority [same- sex] families,” Isaac said. “Part of our job is to remind people that the law is the bottom line.”

Anderton, a number of other Birmingham schools, and several outside the West Midlands have been targeted by religious groups who say they have concerns about teaching materials shared with pupils, which they claim promote LGBT equality and conflict with the teachings of their faith. “As a gay man who’s been very involved in the LGBT movement, I think identity politics have been hugely important historically, and it would be very easy to say identity politics has gone too far,” Isaac said.

But he acknowledged that such politics could be corrosive. “We are living in a world that is more divided, there’s more individualist thinking in relation to what is happening and less empathy, less hope.”

The challenge, he suggested, was to ensure “we don’t end up in the siloed world where everybody is hypersensitive about their own individual interests and less empathetic about how other people are treated.”

He added: “The key issue is how do we move beyond the ‘I’ to the ‘we’, how do we think of ourselves as citizens in a country or in the world who are not just focused on what works for me and my narrow group. How do we ensure that we think about people who are different to us?”

One solution, he suggested, would be for schools to include citizenship classes in their curriculum, to help them become “citizens of the 21st century”.

“Teaching kids about not just same-sex relationships but what it is to be a good citizen would be a really important start,” he said.

Finding common ground where all parties accepted that they were subject to the law that protected minority rights would help remove the “binary” nature that engulfed much of the debate swirling around identity politics, Isaac suggested.

“People do see it as a zero-sum game, and my view is that it’s completely possible to teach the tenets of your faith in school, but at the same time say ‘that child over there has two mothers’. We are asking them to respect somebody else’s lifestyle choice or desire to love someone of the same sex.”

Isaac drew comparisons between the battle to promote equality and human rights and that now being waged to arrest the climate crisis.

“Some things are in crisis, particularly in relation to what is happening to disabled people. We’ve made progress in other areas, LGBT being the obvious one, but when I look at gender and race I think we’ve made less progress.”