The upcoming bribery trial for New Jersey Democratic Sen. Bob Menendez could have damaging consequences for his party whether or not he's convicted, by sidelining him from Congress just as Democrats gear up to fight the Trump agenda.

The senator is now pleading with a federal judge to alter the trial schedule on certain days so he can return to Washington to vote.

So far, however, the court has rejected these requests, which the Trump Justice Department has decried as a bid for "special treatment."

The timing of the trial, set to begin Sept. 6, is critical. It would fall as Congress returns from the August recess and Republicans prepare to vote on President Trump’s legislative agenda -- potentially covering everything from tax reform to health care to the budget and debt ceiling.

Neither party can afford to lose a single member from the Senate floor. Republicans hold a slim 52-48 majority, and it’s possible the absence of a single reliable Democratic vote could tip the balance on key votes this fall, including possibly another attempt at repealing President Obama’s health care law.

Mindful of this, Menendez earlier this week asked for a trial delay, along with other possible alternative concessions, only to be denied by U.S. District Judge William Walls. While Menendez would be free to skip his trial to attend Senate session, doing so could hurt his standing at the trial -- a scenario he's trying to avoid.

As jury selection began this week in New Jersey, the senator's lawyers came back with a more refined request, asking the judge to alter the trial schedule on select days so he can be present for key Senate votes.

“As the recent vote on whether to repeal the Affordable Care Act demonstrated, the Senate is divided by razor-thin margins on consequential legislation, making Senator Menendez’s absence from any particular vote potentially determinative,” his motion stated.

MENENDEZ TRIAL OUTCOME COULD SHIFT BALANCE OF POWER IN SENATE

The Justice Department fired back in its own brief, saying:

"A bedrock principle of our criminal justice system is that the law does not recognize wealth or title. Many defendants try to evade their criminal trials—but only a United States Senator can try to hide behind the very office he corrupted to avoid accountability to the public for his actions. Every defendant should be treated equally, and no defendant should receive special treatment based on power or privilege. This Court should reject defendant Menendez’s effort to let politics in Washington dictate the trial schedule in Newark."

Congress is poised to hold a number of important votes, including on the federal debt limit, a spending deal to avoid a government shutdown and on a Republican tax reform plan.

But there's more at stake in the Menendez case than this fall's votes. Republicans are salivating over the prospect of a more lasting political consequence should Menendez be convicted and should he leave Congress in the next few months: New Jersey Republican Gov. Chris Christie would name his replacement, meaning the GOP could pick up another vote in the Senate.

White House Press Secretary Sarah Sanders, asked about the legislative ramifications of the Menendez trial, said Thursday that the president will continue to push Congress to repeal Obama’s health care law.

“I’m not sure about the specifics of that case. I know there’s still ongoing judicial process taking place, so I’m not going to get into that,” Sanders said. “But I can tell you that the president continues to be committed to repealing and replacing ObamaCare and making sure that America has good health care and the health care that they deserve."

Menendez is accused of using his Senate seat to help the business interests of Florida eye doctor Salomon Melgen in return for campaign donations and expensive trips. In April, Melgen was convicted in federal court on Medicare fraud charges.

Menendez, who along with Meglen has denied the accusations, has argued it’s important the jury see him in attendance during the trial.

“I want the jury to understand that I fervently believe in my innocence,” Menendez told the Associated Press last week. “If there is a moment where there is a critical vote, I have the constitutional right to go ahead and cast a vote and not be at the trial. I also have a constitutional right to be at the trial. So I will decide which of those constitutional rights I will exercise at any given moment.”

Fox News' Bill Mears and The Associated Press contributed to this report.