Single file often makes it harder to overtake safely. If they’re 2 abreast, you treat them like a car. If you cannot overtake a car doing at most 20 mph, it indicates a pretty serious deficiency in your driving ability.
Jeremy Vine will be after you. Wouldn't worry though as even a Repslo should be faster than he can pedal . . . just
Where’s the letter of commendation wrapped around a posh velvet-lined box containing a gold medal inscribed with the words “For Your Service to Drivers Across this Once Fine Land”? Cos that’s more reasonable IMO.
Where there is no white centre line cyclists must ride in single file if there’s a white line down the middle either solid or broken they can ride two abreast it’s in the Highway Code
2x2 may be easier to pass unless there's dozens of them making like a treble juggernaught. That's what the tw@ts do here.