Labor has for the first time recruited a dedicated advertising agency to target the Greens at the federal election as it tries to stave off the minor party in key inner-city battleground seats.

In a sign Labor is determined to protect its left flank from the minor party, it has hired Melbourne based The Shannon Company – the team behind industry superannuation’s breakout “compare the pair” ads – to develop a campaign specifically targeting seats where the contest is between Labor and Greens candidates.