Russians have spoken, and more loudly than expected. The fall of nearly a quarter in the ruling United Russia party’s share of Sunday’s parliamentary vote shows how rapidly citizens are wearying of the political and economic system created by Vladimir Putin. That this protest was registered in spite of the panoply of dirty tricks used by the authorities – from psychological pressure on workers to vote for the ruling party to repeat voting by busloads of hired hands – makes it all the more potent.

The spell Mr Putin cast over Russia for the past 11 years has been broken. This does not imperil his plans to return as president next March, if only because the authorities control who can stand against him. But Moscow has since Sunday seen its biggest opposition rallies in years; more are planned in other cities. The leadership must think hard how to respond.

One option is the iron fist. But strengthening authoritarianism would be dangerous. Attempting, say, to restrict internet access for the 51m Russians who use it could precipitate exactly the kind of protests the authorities seek to avoid.