Bloomberg's detractors have derided him for trying to impose a "nanny state" in America's largest city, pointing to his bans on smoking, trans fats and the attempt to limit the sale of large sugary drinks. Public health advocates have applauded those same efforts.

Only weeks after New York became the first major city to raise the legal age for buying tobacco to 21, the City Council will vote on a ban that would add electronic cigarettes to the city's Smoke-Free Air Act.

If the bill passes, smoking e-cigarettes - or "vaping" - would be prohibited at public and private venues such as beaches, parks, restaurants and office buildings.

"While more research is needed on electronic cigarettes, waiting to act could jeopardize the progress we have made over the last few years," New York City Health Commissioner Thomas Farley said at a city council hearing on the bill earlier this month.

E-cigarettes are slim, reusable metal tubes that contain nicotine-laced liquid in a variety of exotic flavors such as bubble gum and bacon. As a "smoker" puffs on the device, the nicotine is heated and releases a vapor that, unlike cigarette smoke, contains no tar, which is known to cause cancer and other diseases.

Critics of the law contend that such a ban would do more harm than good.

Richard Carmona, a former US Surgeon General and a current board member at NJOY, one of America's largest electronic cigarette manufacturers, sent a letter to the council recently to urge rejection of the bill.

"I'm extremely concerned that a well-intentioned but scientifically unsupported effort like the current proposal to include electronic cigarettes in New York's current smoking ban, could constitute a giant step backward in the effort to defeat tobacco smoking," Carmona wrote.

The debate over risks versus benefits of e-cigarettes is far from being settled, but a study published recently in the British medical journal, The Lancet, said they are as effective as nicotine patches for smokers trying to kick the habit.

Three states - Utah, North Dakota and New Jersey - and Washington, DC have already passed legislation banning e-cigarettes wherever smoking is prohibited.