The Turnbull government is spending $8 million on a new national security advertising blitz that will run throughout the election campaign.

The new ad campaign – "If it doesn't add up, speak up" – has just kicked off and will run until June 30, two days before polling day.

The ads will run across television, radio, print and online, as well as outdoors.

Government tender documents show the campaign will cost taxpayers at least $8.2 million. The Attorney-General's Department has contracted Sydney-based advertising firm Mitchell & Partners to run the campaign.