This change? IMHO Yes.

It was coming anyway, and it could have been any event that triggered it. The right event at the right time?

But as others here mention, the powers that be are unhappy that the population isn't siding with their position. The government is fine with dissent against Russia because they are "the enemy" in the narrative.

Not to say there hasn’t been creeping authoritarianism, growing mass surveillance, etc. for the last few decades, but it has seemed that this one issue has stood out as utterly unique, especially in the UK in that there was basically bipartisan accord from those in power across all the mainstream political views, and the only “allowed” position from them was uncritical support for that country’s Government and their military actions.

At the same time, there seemed to be a much larger group of people in the normal population who disagreed with those in power than most other issues (when at least some representatives in a major party might roughly align with the people)

Did it happen when people protested Russian invasion? No

Did it happen when people protested China for the treatment of Uyghurs? No

Did it happen when people speak up (no protests, yet) about UAE involvement in Sudan? No

I made my own conclusions based on these and other similar data points.

The uk has specifically banned support for Palestine Action so it's a reasonable conclusion