Gov. Paterson and Mayor Bloomberg want to tax soda to fight obesity and, more notably, help plug the state’s $9 billion gap. But here’s a better way to raise cash: tax lies.

Think about it: A dishonesty tax — aimed at politicians — could bring in way more money than a soft-drink levy ever could.

Based on what comes out of Paterson’s mouth alone, Albany could solve its fiscal woes in about a week.

Plus, a soda tax might push some folks to shun soft drinks (or buy them illegally on Indian reservations, anyway), depriving Albany of the very tax revenue it seeks — whereas lies from pols are forever.

Albany would make a mint.

How would it work?

Much like the soda tax, which Bloomberg says could be set at a penny an ounce, a Lie Tax on politicians could be based on the size of the whopper. For example:

* Paterson’s smears of Caroline Kennedy could be taxed at a modest rate.

* His claim that he always intended to pay for the World Series tickets he got last October might push him into a higher bracket.

* If former Chief Judge Judith Kaye finds that the gov tried to get a woman to drop her abuse case against her ex-boyfriend, Paterson aide David Johnson — well, the tax on that alone could do much to balance Albany’s books.

Other pols, too, would have to pay up — like Bloomberg, when he pretends to care about the city’s sky-high tax rate. And President Obama, when he says his health-care reform will lower costs.

Then there’s the all-time tax jackpot: “I never had sex with that woman” — how handy that Bill Clinton is a New Yorker now.

No, if Albany wants a windfall from a sin tax, forget soda — tax pols’ fibs.

Only one possible hitch: Pols aren’t just liars, they’re also tax cheats.

Hmm. Maybe Charlie Rangel, the now-ex-head of the House tax-writing committee, knows how to deal with that . . .