Remember Lynton Crosby? He was the Australian credited with devising and putting into operation the strategy that won the 2015 general election for the Conservatives.

One of his tactics was the ‘dead cat’ strategy, which Boris Johnson (who had employed Crosby in his London mayoral campaigns) described thus: “There is one thing that is absolutely certain about throwing a dead cat on the dining room table - and I don’t mean that people will be outraged, alarmed, disgusted. That is true, but irrelevant. The key point, says my Australian friend, is that everyone will shout, ‘Jeez, mate, there’s a dead cat on the table!’ In other words, they will be talking about the dead cat - the thing you want them to talk about - and they will not be talking about the issue that has been causing you so much grief.”

When Labour were doing well in the election campaign, Crosby decided it was time for a dead cat manoeuvre and Michael Fallon was deployed to make an outrageous attack on Ed Miliband, telling The Times newspaper that: “Miliband stabbed his own brother in the back to become Labour leader. Now he is willing to stab the United Kingdom in the back to become prime minister.” The media immediately switched attention from Labour’s proposals to Fallon’s allegation.

Could it just be that the Conservatives in government have deployed the same strategy - and this time the dead cat is grammar schools?

They know how much the media love to talk about this topic. They know that the Conservative right-wing could be brought four-square behind the prime minister on grammar schools (though they tend not to mention the consequent secondary moderns, which will appear in much greater numbers). Hey presto, right-wing MPs immediately switched from complaining about progress on Brexit and purred with satisfaction about selection for 11 year olds.

Take politics out of education

For school leaders and teachers, 80 per cent of whom do not want to see an increase in the number of grammars, it is time to make the case against, complete the online consultation survey on the Green Paper and get on with the important job of high quality teaching, learning and assessment.

I have spent the last few months reflecting on what is important in school leadership and teaching, writing down my reflections in a book, ’The School Leadership Journey’, which will appear in November. The manuscript has gone to the publishers today.

You cannot take education out of politics, but it would be good to take some of the politics out of education. Politics is a strange world - and it has rarely been stranger than it is at the present time, with many people becoming disengaged from traditional political discourse. Politicians are held in deep suspicion and are probably less trusted than they ever were, somewhere below estate agents.

The level of trust in teachers and school leaders, on the other hand, is up there with doctors, judges and clergymen. We should make the most of this, with teachers focusing on the highest professional standards and school leaders offering principled leadership to their schools and multi-academy trusts.

In the course of writing my book, I encountered the work of the American academic, Victor Lorenz, who has set out ten characteristics of principled leaders in business, government and the academic world:

1. They put the interests of the institution they serve above their own self-interest.
2. They understand that character is defined by the small acts they perform when nobody is looking.
3. They recognize that respect must be earned over time but can be lost in an instant.
4. They promote their people, not themselves.
5. They take responsibility for failure - by themselves and by others.
6. They share credit for their successes with the individuals who made them possible.
7. They are consistent and predictable in their decision-making.
8. They strive to do what is right rather than what is expedient.
9. They do not fear making unpopular decisions and clearly communicate their rationale for making such decisions to those affected by them.
10. They only serve institutions that do not require them to compromise their principles.

Although written mainly from the business perspective, these characteristics fit well with the principled leadership of schools in the 21st century.

Principled leadership promotes clarity about every aspect of school life and communicates to everyone connected to the school a consistent, honest message about what is possible. Staff and students flourish in schools under principled leadership.

So, when the prime minister states that a new generation of grammar schools will be inclusive, we know that to be a contradiction in terms and suspect that we smell a dead cat.

That’s the time for school leaders and teachers to focus on their values and their principles, and to remind the politicians that, while they talk about changing school structures, it is high quality teaching, learning and assessment that really makes a difference to the lives of young people.

John Dunford is chair of Whole Education, a former secondary head, general secretary of the Association of School and College Leaders and national pupil premium champion. He tweets as @johndunford