(CNN) The Justice Department filed a notice Friday to re-try Democratic New Jersey Sen. Bob Menendez on federal bribery and corruption charges.

An 11-week trial last fall resulted in a hung jury. Prosecutors had accused the senator of accepting bribes from Dr. Salomon Melgen, a wealthy ophthalmologist in Florida, in return for political favors.

Menendez and Melgen pleaded not guilty to all charges.

In a statement, the Justice Department requested the court set "the earliest possible date" for the new trial.

"Sen. Menendez and Dr. Melgen were indicted in the District of New Jersey on charges that included conspiracy, bribery, and honest services fraud," the department said. "The decision to retry this case was made based on the facts and the law, following a careful review."

The retrial could become a major headache for Democrats in the 2018 midterm elections.

Menendez is running for re-election this year despite his legal trouble and already has become a punching bag for national Republicans, who have sought to tie him to other Democrats on the ballot this year.

Three Republicans are running to oppose Menendez, including Jeff Bell, the party's nominee against Democrat Cory Booker in 2014, and Army veteran Rich Pezzullo.

Menendez's seat could still be safe in his blue state: No Republicans currently facing Menendez have shown any serious fundraising efforts, and Menendez has $3.9 million in the bank, according to his latest campaign finance report.

Republicans, however, have had recent success in the state. Though former GOP Gov. Chris Christie exited with record low approval ratings, he was elected twice. In last year's gubernatorial election, Democrat Phil Murphy won by 13 percentage points -- a high mark that Menendez is unlikely to top.

Democrats who closely watched Menendez's first trial as they weighed bids for his office, including former Sen. Bob Torricelli, ultimately decided against challenging him in the party's primary.

"To those who were digging my political grave so that they could jump into my seat, I know who you are, and I won't forget you," Menendez said after the hung jury in November.

On Friday the senator's office issued a statement batting away the case against Menendez as baseless.

"We regret that the DOJ, after spending millions and millions of taxpayer dollars, and failing to prove a single allegation in a court of law, has decided to double down on an unjust prosecution," the statement read. "Evidently, they did not hear the overwhelming voices of the New Jerseyans who served on the jury this fall. Sen. Menendez fully intends to be vindicated -- again."

First trial

November's mistrial was a serious blow to the Justice Department, which has investigated Menendez for nearly five years.

After the trial ended, one juror told reporters the jury was split 10-2 on all counts in favor of acquittal.

At the time, the senator said he felt vindicated.

"I want to thank the jury, 12 New Jerseyans who saw through the government's false claims and used their Jersey common sense to reject it," he told reporters outside the courthouse, before blasting the Justice Department.

"The way this case started was wrong, the way it was investigated was wrong, the way it was prosecuted was wrong and the way it was tried was wrong as well," he said. "Certain elements of the FBI and of our state cannot understand or, even worse, accept that the Latino kid from Union City and Hudson County can grow up and be a US senator and be honest."

Shortly after the mistrial, Senate Majority Leader Mitch McConnell, R-Kentucky, called for a Senate Ethics Committee investigation.

The charges

Menendez faced charges of conspiracy, bribery and honest services fraud related to allegedly abusing the power of his office that could have carried decades in prison. Prosecutors said Menendez pressured high-level officials in the Obama administration and other career diplomats to help Melgen resolve his business disputes in exchange for political contributions, a luxurious hotel suite at the Park Hyatt in Paris and free rides on Melgen's private jet that Menendez failed to report on his Senate disclosure form.

Defense lawyers argued that Menendez and Melgen were longtime friends with no corrupt intent to commit a federal crime.

Kirk Ogrosky, an attorney for Melgen, said they are "disappointed that this Justice Department would re-try the case."

"Anyone who watched the testimony, reviewed the exhibits, and spoke to the jurors and the alternates in the first trial knows that this prosecution was ridiculous and should never have been brought," Ogrosky added.

Prosecutors relied mostly on circumstantial evidence to prove their case -- spending the opening weeks of the trial painting a jet-setting lifestyle of the rich and powerful before ultimately turning to the "official acts" they argued Menendez did to help his friend.

They accused the senator of pushing officials to help resolve an $8.9 million Medicare billing dispute in Melgen's favor, while the defense team claimed at trial that Menendez was focused on the fact that the billing policies at issue were conflicting and the drug companies were enjoying a windfall.

Similarly, when several State Department witnesses testified that Menendez had threatened to hold a congressional hearing if they did not intervene in a contract dispute between Melgen and the Dominican Republic over cargo screening at the nation's ports, the defense said the senator was troubled by port security more generally.