Over 125,000 March in London Against Israel's Gaza Genocide

It equates to about one in five hundred and fifty people, which is less than 0.5% of the population, so I can understand why the government feels content to overlook it.

Unfortunately, protests are largely inneffective until wide spread disruption is caused. If you want the government to take notice people need to feel strongly enough to the point that they're willing to risk prison sentences and most people are far too comfortable to risk that.