Washington (CNN) A pair of Republican-led bills in Florida's state legislature would require certain ex-felons, whose voting rights were restored last November in a statewide referendum, to pay fees before they can head to the polls.

Republicans argue that the fees are part of an ex-felon's sentence and are thus obligatory. Democrats, however, charge that the Republican effort is an attempt to institute a modern-day "poll tax" to prevent ex-felons from voting.

In November, Florida voters approved a constitutional amendment allowing convicted felons who complete all terms of their sentence, including parole or probation, the right to vote, except those convicted of murder or a felony sexual offense. Amendment 4 passed with nearly 65% of the vote, exceeding the 60% threshold required to become a law and restoring voting rights to about 1.4 million Floridians.

The addition of so many new voters could have a profound impact in a place where statewide contests are often decided by slim margins. An analysis conducted last fall by the Tampa Bay Times and Miami Herald found Democratic and black voters were far more likely to have lost their voting rights because of a felony conviction, and in the same election that approved the referendum, Democratic US Sen. Bill Nelson was ousted by Republican Rick Scott by a little over 10,000 votes. In 2016 , Donald Trump captured the Sunshine State by less than 113,000 votes over Hillary Clinton, or 1.2% of the vote.

Soon after the referendum was passed, Republicans -- including the state's newly inaugurated governor, Ron DeSantis -- have said the law was unclear as to how it should be implemented and what constitutes the completion of a sentence.

On Tuesday, the state House Criminal Justice Committee approved a bill that would require eligible felons to pay back all court fines and reparations, defining a felon's sentencing to include "any cost of supervision or other monetary obligation." The House bill also would define which crimes count as felony sexual offenses and murder. A similar bill has been introduced in the Florida state Senate's Criminal Justice Committee and the panel plans to vote on that measure Monday.

"All we're doing is following statute," the committee chair, Republican state Rep. James Grant, argued Tuesday when he addressed the committee, whose 10 Republicans all joined to pass the bill over the objections of the panel's five Democrats. "All we're doing is following the testimony that was presented before the Florida Supreme Court explicitly acknowledging that fines and court costs are part of a sentence."

Florida state Sen. Jeff Brandes, the Republican vice chairman of the Senate Criminal Justice Committee, told CNN on Friday that there was a general consensus that the language of Amendment 4 needed to be "further refined and honed" and that their bill intends to establish a "standard interpretation across the state."

But Democrats say the House bill is too broad, allowing for fees to be accrued beyond what was court-ordered to be required to vote. The Brennan Center for Justice, a division of New York University School of Law that studies democracy and justice issues and helped draft Amendment 4, say the bills aim to undermine the referendum's intent and would disenfranchise voters who cannot afford to pay their financial obligations.

"The legislature is essentially ensuring that there would be permanent disenfranchisement for many people, and basically for people who aren't as well off," Sean Morales-Doyle, a counsel for the Brennan Center, told CNN.

Democratic Florida Rep. Adam Hattersley argued Tuesday before the committee that "it's blatantly unconstitutional as a poll tax" -- a Jim Crow-era law that effectively blocked African-Americans from voting by requiring them to pay a fee. Other prominent Democrats, including US Rep. Alexandria Ocasio-Cortez of New York and former Democratic presidential nominee Hillary Clinton, also slammed the bill.

Grant, however, said Tuesday that "to suggest that this is a poll tax inherently diminishes the atrocity of what a poll tax actually was." CNN has reached out to Grant's office for additional comment.

Brandes, meanwhile, asked, "Do they believe people paying restitution is a poll tax?"

The fees and fines that felons are ordered to pay are wide-ranging but significantly high for an individual leaving prison, especially if they're unemployed. They can range from a couple hundred to tens of thousands of dollars, said Lisa Foster, the co-director of the Fines and Fees Justice Center, a group that aims to eliminate fees in the US justice system. And in Florida, all the court charges that are unpaid after 90 days are referred to private debt collectors, who are allowed to add up to a 40% surcharge on the unpaid court debt, according to the Brennan Center

"No one is saying they shouldn't pay," Foster said, "but that doesn't mean you hold voting rights hostage."