Enforcing a smoking ban on Douglas high street would be "difficult", the council has admitted.
A petition calling for lighting up or vaping to be outlawed from Castle Street to Duke Street has attracted more than 700 signatures.
Campaigners want to see the creation of a "smoke free zone" in the Isle of Man's main shopping area.
Council leader David Christian said that although "well intended", it would be "very difficult to actually police".
Wardens already face problems enforcing a ban on littering in the area, he added.
Mr Christian added: "Even if we see them throw something down, we've got to ask them to pick it up first before we can actually issue them with a fixed penalty notice."
Petitioners said it was "wrong for people who do not wish to inhale hazardous toxins in the air to be subjected to this while trying to go about their daily shopping".
While smoking in indoor public spaces came into force in the island in March 2008, lighting up outdoors is still permitted.
Mr Christian said that unless the council "went down the road of a real nanny state" by increasing CCTV in the area, extending the smoking ban would be unworkable.