DARWIN. As far as campaign stunts go, it doesn't get more blatantly political than a visit to an Australian Border Force patrol boat.

But reporters arriving to the carefully staged event on Tuesday were warned not to photograph Malcolm Turnbull alongside the Border Force's logo, which proudly adorned the Cape Jervis docked in Darwin.

The Border Force was keen to avoid being politicised, the PM's staffers explained, even as cameras were being assembled right behind them for a press conference.