I teach in a mixed comprehensive in a constituency where on 8 June over two-thirds voted Labour, where an overwhelming majority voted Labour in the most recent mayoral vote, and where Labour has been the largest party on the local council for decades. A large majority of staff at our school vote Labour.

As a Labour supporter, this thrills me; as a teacher, it makes me question whether my school is doing enough to help our students appreciate other viewpoints.

As teachers, we are bound by the 1996 Education Act to present different political beliefs impartially and to not promote partisan political views. Yet, probably unintentionally, my school is often an echo-chamber for the leftwing views of its staff and its students’ parents.

Views that fall outside the accepted liberal-left spectrum get short shrift in my staffroom. I have watched teachers react incredulously – almost to the point of tears – when colleagues have tried floating a reasonable case for Brexit. This would be harmless enough if it did not put in doubt their ability empathise with views opposed to their own.

Unfortunately, I see that lack of empathy in the classroom. It worries me that few of my colleagues seem to understand why Conservatives think as they do. In lessons discussing the general election, I have seen teachers make half-hearted attempts to present a rightwing line of reasoning about the major issues. Their bored or frustrated tone of voice says it all.

In theory students are introduced to a range of ideologies through studying government and politics. But I have only heard Labour politicians being criticised by fellow teachers for being too rightwing. We have had assemblies celebrating feminists and the campaign for a living wage, which are excellent and informative, but with no attention given to right-of-centre subjects (none that weren’t heavily critical, anyway).

The latter were balanced presentations insofar as they covered arguments on both sides, although dissenting views were always delivered under an arched eyebrow. Perhaps this is unavoidable. After all, I do not think it is unreasonable for teachers to share their political views, provided they make caveats about these being personal views. In its guidance to schools, Ted Huddleston of the Citizenship Foundation warned that “it does young people no favours to shield them from views they are likely to encounter in society”.

In schools like mine, however, where students are already immersed in political uniformity, we do them no favours by merely presenting different views. What we should do is offer compelling counter-narratives, so that students can appreciate why people might reasonably hold different political views from their own, regardless of differences in background.

Teachers at my school didn’t tell students to vote Labour on 8 June – they are just as nervous about being overly partisan as many others in the profession. But by shaping our students’ climate of political opinion, my colleagues implicitly define what students come to regard as reasonable and acceptable political views.

It often seems like few other authority figures in my students’ lives are preparing them for life outside their Labour bubble, where, for example, austerity is not automatically a term of abuse, and welfare not always accepted as a good thing. The net effect is to restrict their intellectual curiosity about, and ability to empathise with, others of different political persuasions.

I see evidence for this every week when I hear otherwise bright and articulate students justify their political opinions with vague, lazy arguments. As John Stuart Mill foresaw, since they have never learned to defend value judgments that seem entirely natural to them, they will struggle to respond to their opponents beyond the school gates.

This is about more than education. With our politics increasingly polarised, it saddens me to see my students being initiated – deliberately or not – into an essentially Manichaean view of politics, with a checklist of “goodies” (leftists, trade unions, Corbyn) and “baddies” (Tories, Brexiteers, anyone who uses the phrase British values without irony).

Given this, don’t my colleagues and I have a responsibility to do more than offer, in the words of the Education Act, “a balanced presentation of opposing views” – which in practice is often just paying lip service? Ought we not to make a habit of playing devil’s advocate?

Only an active commitment on the part of all teachers to resisting the status quo in our students’ lives – whatever that might be – will prepare them for meaningful political participation. This involves making the effort to articulate an intellectually rigorous and persuasive case for political views far removed from ours – and from theirs.

Teaching active empathy with different political views than our own might require more time and work on our part but it would better prepare students to be able to reach across political divides in later life. Surely we could use some of that right now.

Follow us on Twitter via @GuardianTeach, like us on Facebook, and join the Guardian Teacher Network for lesson resources and the latest articles direct to your inbox

Looking for a teaching job? Or perhaps you need to recruit school staff? Take a look at Guardian Jobs, the education specialist