John Oliver 'not very funny' - Bill English

Prime Minister Bill English has responded to John Oliver's mocking of the National Party's legal battle with Eminem, saying he "isn't very funny".

The funnyman took aim at the case on his HBO show Last Week Tonight, taking particular delight in video of 'Lose Yourself' being played to silent and motionless lawyers in the courtroom.

English says he hasn't seen the latest segment, but has viewed other bits of the show and is not a fan.

"Some of the stuff I've seen he does isn't very funny," says English.

The National Party leader-turned-comedy critic cannot recall what specific work of Oliver's he has seen and disliked, but confirms he has no intention of watching the latest clip.

"I just hope he's funny. It's a serious business in the court - that's where it's got to be dealt with. If we attract attention, it doesn't bother me too much."

The court case is scheduled to finish on this week, while Oliver's next Last Week Tonight episode will be screened on HBO in the US on Sunday night (local time).