Nothing justifies yesterday's attack in Manchester. No excuses can ever be made for murder. That is what this was. My sympathies go to all involved, their communities, and to the police officer who has to carry the burden of having killed the attacker to prevent what was, it seems, entirely reasonably believed to be a greater risk.

There is, however, one thing to add. A politician - and I did not catch who, but he was an elderly man - was interviewed on Channel 4 News last night, saying that over the last two years, antisemitism has become normalised in middle-class society in the UK. His inference was clear: what he was implying was that criticism of Zionism is antisemitic and must cease as a result of an attack like this.

That is not true. That is the logic that underpins what Trump is doing in the USA.

Zionism is not to be equated with Jews. There are Jews who are not Zionists. The two are, quite simply, unequatable as they are not the same. One is a political belief system, the other describes the adherents to a faith that has come to define an ethnic group.

There are Jews who oppose the existence of Israel.

There are Jews who think Zionism is racist - as it clearly is. It declares Jews a superior race with greater rights than Arabs and Palestinians. That is not true.

And Zionism might lead to support for what the government of Israel is doing, but the government of Israel does not represent all Jews, even within that country.

I defend the right of Israel to exist, as I have, since I first thought about this issue as a student fifty years ago. But as I have also made clear, I think the right of Palestine to exist is as certain and obvious.

But I will not support the Israeli government's actions when they are wrong. At present, they are pursuing a genocide. That government's policy - not that of Jews, even if they all happen to be Jewish - is racist and fascist. And it is not in any way antisemitic to say so.

In that case, to suggest that because of this wholly unjustified attack, which I condemn absolutely, I am no longer allowed to point out that the actions of some people are wrong is discriminatory, a denial of my human rights, and a denial of reality, because that genocide is happening, and many people died as a result of it in Gaza yesterday.

Saying that does not make me an antisemite, as that politician on Channel 4 last night implied. It reflects the fact that I respect the rights of all Jews to be treated equally in this world, as I respect the rights of all others to be treated in the same way. I cannot be an antisemite for upholding Jewish rights. Those who say I am are the real antisemites: they are saying the Jews are different, and that I will not stand for. Jews are people, like all other people. They are not better, worse, or different. They are people to be judged as all others are.

They should not ever be attacked for their faith, beliefs, or ethnicity.

They have a right to live in peace.

That right must be protected.

But that does not afford some Israelis, whether Jews or not (and not all in the IDF, for example, are Jews), the right to engage in war crimes, and no one can claim that right exists.

So, let the country mourn this event. Let us condemn the lone attacker, who appears to have no previous known links to terrorism, according to good reports this morning. What he did was utterly wrong and to be condemned. But let us not use that as a reason to silence those who oppose violence, whoever uses it against others.  We have that right. And I will continue to exercise it.