Kirstie Allsopp admitted this week to smashing her sons’ iPads when they continued to flout the Allsopp house rules for playing Fortnite. “Not in a violent way,” she told Channel 5’s Jeremy Vine. She “banged” the devices “on a table leg” while her sons, aged 12 and 10, watched. There has been a backlash to her comments online, and she has since left Twitter. I can, however, sympathise with the level of despair behind this act.

“It’s passing a terrible message to children,” says Suzie Hayman, an agony aunt and the author of Parents and Digital Technology. “It’s saying: ‘This is how you solve arguments – you smash something.’ Any violence is bad,” she says, even a gentle bang of a tablet on a table leg.

Confiscation is fine, Hayman says. However, she adds: “When you make excuses for any form of hitting out, whether it’s against a person or an object, you are still hitting out.” So, what can a parent do when a child refuses to reduce their screen time in line with house rules?

First, try to “respect what they are doing and why”, Hayman advises. If your child is obsessed with Fortnite and Player Unknown’s Battlegrounds, as Allsopp’s apparently are, ask them what they like about those games. Request a tour. Recognise any positives: maybe the game requires collaboration or strategy.

Next, discuss house rules. If there is to be no screen time in the hour before bedtime, or at mealtimes, make that clear. Set sanctions for when rules are broken. “Make it an agreement,” Hayman says. “Write it down. Hang it up.” Then put the legwork in, even when tired, to police the rules.

However, the older the child, the tougher it can be to define boundaries and apply consequences. “When they hit adolescence, if you say ‘no’ [to screen time], they are going to say ‘I’m off’,” says Angharad Rudkin, a clinical psychologist who specialises in child development. “It becomes a lot more about compromise and co-operation. What are the advantages and disadvantages of you being on the iPad for four hours? Let’s work out a compromise. When you’re on your tablet, what you’re not doing is homework, face-to-face contact, exercise ...”

The key is not whether you can agree, but whether, by understanding each other’s position, both parties are able to behave in a way that is agreeable. (And, no, it is not easy.)

Last, don’t forget to play fair yourself. Hayman discovered in the course of writing her book, for instance, that her husband “would get quite fed up” if she read emails in the evening, so now she avoids doing so after 6pm. Rudkin has no devices in her house: her phone is always in her bag; she and her partner are not on social media. Rules work both ways – so prepare to be called out on overuse of technology by your children in return.