On Tuesday, New Yorkers will face with a ballot question on whether to hold a constitutional convention. Every 20 years, the question appears on the ballot, giving New Yorkers a unique opportunity to open up the state constitution and make changes.

But as State House Reporter Zack Fink explains, that is making the establishment of elected officials and unions very nervous, and they are urging voters to reject the convention, which is also known as "con-con."

As the vote over what's known as "con-con" approaches, it's an all-out-battle.

"Why are New York State's most trusted newspapers saying 'Yes' to the constitutional convention," a narrator says in part of a commercial from reformers hoping to change the state constitution. "On November 7th, it's your opportunity to say 'Yes' to the New York State constitutional convention. Vote 'Yes' on Question One."

A sleeker ad, however, is indicative of the much better-funded campaign against a constitutional convention, which is being bankrolled by the unions and others.

"Sounds harmless, right? Well, that is exactly what the corrupt politicians and special interest groups are hoping you think," a narrator says in part of the ad. "But the truth is, a constitutional convention would be nothing short of a disaster."

In our exclusive NY1/Baruch College City Poll, 37 percent of city residents said they would vote for a constitutional convention. 29 percent said they would vote against it, with 18 percent undecided.

But the referendum is statewide and other polls show the convention is likely to be defeated.

"Our big concern is, frankly. that it is a big waste of money. The legislature is paid to do the job," CWA Political Director Bob Master said. "We don't need to convene a special meeting, at which there will be an unlimited amount of expenses, lobbyists, and legislators up there for an indefinite amount of time to look at a bunch of issues that the legislature rightly needs to deal with."

At the 11th hour on Monday, Gov. Andrew Cuomo changed his position and came out against the convention. Supporters, meantime, say voters are smart enough not to harm the constitution.

"The voters will decide what is right and what is wrong, and to imply that special interests will take over is not really giving New York voters the credit that they deserve," Betsy Gotbaum of Citizens Union said. "So I'm hoping that people will vote yes. I'm hoping that we will get delegates to go to the convention."

There are two other ballot initiatives that New Yorkers will see when they vote Tuesday. Question Two would strip an elected official of his or her public pensions if he or she is convicted of a felony.

Question Three would allow upstate municipalities to make infrastructure improvements even if they are located on protected land.