STATEN ISLAND, N.Y. -- When it comes time to vote on President Donald Trump's tax plan, Rep. Daniel Donovan is prepared to reject a second major policy proposal from the president.

The tax plan would eliminate federal income tax deductions for state and local taxes (SALT), a change that Donovan and other Republicans from New York argue would be a double tax on their constituents.

The tax plan would double the standard deduction, increasing to $24,000 for a married couple, and lower income taxes overall, which the administration says would amount to a tax savings.

"Under the president's proposal, 95 percent of Americans will find it more advantageous to take a standard deduction because it will be bigger than their combined state/local property taxes," according to a White House spokesperson.

But Donovan (R-Staten Island/Brooklyn) and six other Republican congress members haven't seen numbers that support that, and penned a letter to Treasury Secretary Steven Mnuchin, opposing the plan if it would mean an increase for taxpayers.

For more than 100 years, people filing taxes deduct what they have already paid in state and local income tax, so as not to pay federal income tax, or what would be a double tax.

But removing that deduction may amount to just that, the Congress members argue.

"Double taxation belies the basic philosophical underpinning of a smaller, leaner government," the letter states. "Citizens are forced to spend a percentage of their earnings on state and local taxes or face severe legal consequences. The portion of their income dedicated to state and local government coffers, therefore, is not "earnings" under even the most liberal definition. To tax citizens on income they never see - regardless of the massive amounts of revenue it may raise for the federal government - is contradictory to our basic perspective on government largesse."

In addition to Donovan, Congress members Peter King, Elise Stefanik, Claudia Tenney, John Katko, John Faso and Lee Zeldin signed on.

Donovan met with Mnuchin and national economic director Gary Cohn and expressed his hesitation to support the tax plan if it meant a double tax.

"They told me they will prove to me -- they haven't yet -- that with the double standard deduction and the lowering of the tax brackets that everyone would benefit," he said. "My position is, I'm not going to vote on a tax reform bill that's going to increase the taxes of the people I represent."

If it's lower "then I would consider voting for it," he added.

But the Republican congressman is also concerned that other deductions may be axed.

"The state and local tax deduction isn't the only thing that I'm concerned about," he said.

While the plan says taxpayers can still claim a deduction for mortgage tax and charitable donations, Donovan fears that language requiring people to choose one or the other may be in the final bill.

The new federal income tax brackets would be:

-0 percent for single filers making up to $25,000

-10 percent for $25,001 to $50,000

-20 percent for $50,001 to $150,000

-25 percent for $150,001 and up

"With this huge reduction in rates, many of the current exemptions and deductions will become unnecessary or redundant," the Trump tax plan states.

CUOMO PLANS MEDICAID TAX REBUTTAL

While Congress is weighing Trump's federal tax plan, implications from the American Health Care Act (AHCA) that passed the House in May continue to play out at the state and national levels.

To get some Republicans on board what was initially a failed attempt to pass the GOP bill, an amendment from upstate Congressmen John Faso and Chris Collins gives New York counties outside the five boroughs a combined $2.3 billion break in paying Medicaid taxes.

That cost would fall onto the state, and Gov. Andrew Cuomo has proposed a Faso-Collins Tax to make up the difference.

The Senate, which won't vote on the AHCA until it returns from its July 4th break, included the amendment in its version of the bill.

"By including the reckless Faso-Collins amendment, this bill will force every resident of this state to pay a 'Faso-Collins Federal Tax' added onto local property taxes to make up the $2.3 billion shortfall created by their proposal," Cuomo threatened.

Details of that tax have not been released, and while lawmakers -- who ended their session last week -- are returning to Albany on Wednesday to give Mayor Bill de Blasio another year of mayoral control of New York City schools, the tax doesn't appear to be on the agenda.

"The amendment was one of the many reasons I voted no," Donovan said of the AHCA.

"It's the exact thing I predicted. The governor was going to make up the difference. What we ought to do is exempt New York City from that county tax because we're already paying our share."

Cuomo's office didn't respond to a request for comment on the details of the tax proposal, including whether the five boroughs, which don't get relief from the more than $5 billion in Medicaid taxes under the Faso-Collins Amendment, would also have to pay the new tax.

"I always thought the burden was going to fall on the people of our city," Donovan said. "My plea to [Cuomo] would be to exempt the five counties of New York City."