BOSTON (CBS) – Whitey Bulger’s attorneys filed a motion Thursday to adjourn his racketeering trial until July 16 because they’re having trouble getting ready for each day.

But Judge Denise Casper denied that request.

READ MORE: 2 Massachusetts Men Killed In Fiery Las Vegas Crash

Check: Live Trial Updates From Court

Bulger is on trial in federal court in South Boston, charged in connection with 19 murders.

“Simply put, the defendant’s counsel have hit a wall, and are unable to proceed further without additional time to prepare for upcoming witnesses. Counsel have struggled mightily to be ready for each day of the trial since it began on June 3, 2013, working seven days a week and extraordinarily long hours,” Bulger’s attorneys J.W. Carney and Hank Brennan wrote in the filing Thursday.

“A major problem has been the delay in the receipt of discovery from the prosecution,” the attorneys wrote, claiming they don’t have enough time to prepare their response.

“These discovery lapses may not be intentional, and may reflect that the prosecution team is overwhelmed as well. Nonetheless, it has put the defense team in an untenable position, especially as it continues to review earlier-produced discovery that now amounts to almost 400,000 pages. There is a physical and mental limitation on how much work can be done by the defense team, and a brief adjournment of the trial will allow counsel to be prepared for the upcoming witnesses,” Carney and Brennan wrote.

READ MORE: Annissa Essaibi George: Any Suggestions Of Ties To Donald Trump Are 'Gross Statement'

They also claim that Bulger, 83, is run down by the long days.

“The trial schedule, especially on Thursdays, has exacerbated this problem. The defendant is awaken at 4:00 am every trial day, and by the end of his travel back to Plymouth, this 83-year old man is exhausted. Meaningful interaction with counsel in the evening is impossible.”

In court Thursday morning, federal prosecutors objected to the delay request.

As for Bulger’s condition, Assistant U.S. Attorney Zachary Hafer said the reputed gangster had “16 years to relax in California,” referring to Bulger’s time in hiding in Santa Monica, where he was arrested in June 2011.

Casper did agree with Carney’s request to stop the practice of going late, to 3:30 p.m. on Thursdays.

MORE NEWS: Westboro Wrong-Way Crash Leaves Multiple People With Serious Injuries

The trial sessions will now end at 1 p.m. every day.