Simon Bridges says it will be on the Speaker if claims his expenses leak came from inside his own party, turn out to be false.

National's pushing forward with its own inquiry - after Trevor Mallard called the parliamentary one off.

Following an anonymous text from someone alleging to be both the leaker and a part of National's caucus was sent to Mallard, Bridges and parts of the media.

But Simon Bridges told Mike Hosking there is no concrete evidence.

"There's strong, as I have said to you before, forensic ability to do this, to work out if it is one of my numner. My point is, if it isn't well then that's on Trevor Mallard."

LISTEN ABOVE AS SIMON BRIDGES SPEAKS WITH MIKE HOSKING