This an example from EnergySage describing phantom load, just as the Loop one that Elegran linked to does. The former is an American site so the example is in dollars and will not represent UK energy costs but the principle is the same:
For instance, say you leave your laptop computer charger plugged in all day, every day of the year. That charger pulls an average of 4.42 watts of power even when it's not actively charging your computer, meaning that the charger will use nearly 40 kilowatt-hours of electricity every year. If your electricity costs 15 cents per kilowatt-hour, you would add $6 to your annual electric bill.
While $6 does not sound like much, consider that the dollar impact is just from leaving a single charger plugged in all year round. When you add in the phantom loads coming from TVs, computer monitors, cable modems, and more, you could end up with a large enough phantom load to effectively add an additional monthly electricity bill every single year.
At the end of the day, though, the best way to ensure that an appliance or device isn't a source of phantom loads is to unplug it altogether. It can't pull electricity from the grid if it's not plugged into an outlet after all.
And this video from Hawaiian Electric:
www.youtube.com/watch?v=3d8gCA-ViaY
It says anything with an LED clock which was the point made by OP who has five clocks on five appliances.
It may be a minimal saving per appliance but it adds up. Nobody is saying someone has to unplug appliances but there may be small savings to be had if you do.
As I said upthread, just a few pence a day can add up to a large saving over a year. For single-income low energy users burdened with large standing charges that they can do nothing about, that can represent a sizeable and worthwhile saving.
