A CFMEU administration senior officer has pledged that the union will campaign against Coalition leader Peter Dutton during the election, despite promises the construction union would not engage in party politics while under administration.

CFMEU national secretary and Victorian branch executive director Zach Smith posted a video to members last week targeting Dutton for his promise to deregister the union if elected and promised members the union would “fight this threat tooth and nail”, as it would have done before the administration.