Dunbar plays Supt Ted Hastings in the BBC drama, which is written byJed Mercurio, and Compston plays DS Steve Arnott.
Speaking to The Mirror, McClure said: “You can have a laugh and if anything it’s Adie who gets the brunt of it having to put up with me and Martin acting like a pair of school kids around him. There’s a perfect dynamic.
“The reality of it is of course we have, of course we have p***** each other off. It would be wrong of me to say ‘that has never happened’ as that would be a lie.
“But in the same way it is with family, it’s never something so bad it’s not repairable. I might not have had any sleep that night.
“He might not have had any sleep or loads of lines to learn, you get up to set you are knackered, there’s a lot going on.”
Before it was broadcast, Mercurio has said killing off the three stars of Line Of Duty is “never far from my thoughts”.
“We all get on brilliantly, but everybody knows that we’re serving something bigger than ourselves, which is Line Of Duty, and one of the things about the show is that nobody’s safe; it’s what keeps the audience on the edge of their seat.
“So, I know that it would be a sad day, but I think all the main cast realise that it’s possible, and we talk about it, we joke about it, and it’s something that no one would relish, but everybody would understand.”
Filming of the sixth series of the hit show began last year, but had to be paused because of disruption caused by the coronavirus pandemic.
It continues this Sunday on BBC 1 at 9pm.