Momentum’s latest political advert is causing a splash on the left and the right.

Finally someone said it pic.twitter.com/FoPN9jmIbZ — Momentum (@PeoplesMomentum) July 27, 2017

One of the underreported trends of 2016 was that British political parties learnt how to make high-quality videos at low-cost, and Momentum have been right at the front of that trend.

This advert is no exception: an attack that captures and defines its target and hits it expertly. The big difference is that this video doesn't attack the Conservative Party – it attacks people who voted for the Conservative Party.

Although this is unusual in political advertising, it is fairly common in regular advertising. The reason why so many supermarket adverts tend to feature a feckless dad, an annoying clutch of children and a switched-on mother is that these companies believe that their target customer is not the feckless father or the children, but the mother.

The British electorate could, similarly, be thought of as a family. What happened at the last election is that Labour won votes of the mum, who flipped from Conservative to Labour, got two of the children to vote for the first time (but the third stayed home), but fell short because the dad, three of the grandparents, and an aunt backed the Conservatives. (The fourth, disgusted by the dementia tax, decided to stay at home.)

So the question for the party is how do they do better next time. Do they try to flip the votes of Dad and the grandparents? Or do they focus on turning out that third child?

What Momentum are doing in this video is reinforcing the opinions of the voters Labour got last time by mocking the comments they’ll hear round the dinner table when they go to visit their parents and grandparents. Their hope is that this gets that third child out and voting next time. For a bonus, perhaps that aunt will sympathise with the fact her nieces and nephews, working in the same job, in the same town, cannot hope to get on the housing ladder as she did and will switch her vote from Tory to Labour.

(This is why, if, as Toby Young and Dan Hodges do, you see the video as “attacking Labour voters”, you haven’t quite got the target of the advert or who exactly voted Labour last time.)

That could be how messages like this work for Labour at the next election. But the risk is that Mum decides she quite likes Dad and switches back to the Conservatives – or that the second child is turned off by the negativity. And don’t forget the lingering threat that now the dementia tax is dead and gone, all four grandparents will turn out for the Conservatives next time.