Abu Ghaith pleaded not guilty when he appeared in court last month. Reuters

A landmark civilian trial of Osama bin Laden's son-in-law may be delayed until next year due to budget cuts arising from the sequestration, a US court heard Monday.

Lawyers for alleged al-Qaida spokesman Suleiman Abu Ghaith said that due to a mandatory five-week furlough of all federal defence lawyers in New York, the prosecution may have to be pushed back from September to January 2013.

US district judge Lewis Kaplan said it was "extremely troublesome" that a trial of such importance could be affected by government cuts.

In a further development, defence attorneys suggested that they intend to ask for court hearings to be moved away from the federal court in lower Manhattan – situated just a few blocks from the site of the September 11 attacks – due to the potential of a jury being prejudiced.

Abu Ghaith faces an indictment that includes the charge of conspiring to kill US nationals. The 47-year-old Kuwaiti is the alleged spokesman of al-Qaida, and the son-in-law of former terror network chief Osama bin Laden.

Prosecutors say he was summoned on the evening of the September 11 attacks by bin Laden and asked to assist in al-Qaida's campaign against the West.

The following morning, Abu Ghaith – along with bin Laden and then al-Qaida deputy Ayman al-Zawahiri, released a video in which he warned the US that "a great army is gathering against you" and calling on "the nation of Islam" to fight "the Jews, the Christians and the Americans".

He later gave a speech in which he warned Muslims "not to board any aircraft and not to live in high rises".

At Monday's hearing, lawyers for the suspects told the court that they were considering filing a motion to change venue.

Outside the courtroom, defence attorney Martin Cohen was asked if he thought it possible to find an impartial jury, given the courtroom's proximity to where nearly 3,000 people died on September 11, 2001.

"That is a question that we are mulling over," Cohen said. He issued the same response when asked where he thought an unbiased jury could be found.

If the case is moved from New York, it will come as a blow to the White House, that has long sought to try terrorists – including those connected to the September 11 attack – in a civilian courtroom in New York, rather than in military hearings at Guantánamo Bay.

After Abu Ghaith's first appearance last month, senator Mitch McConnell accused President Barack Obama of putting politics above security concerns.

"The decision of the president to import Suleiman Abu Ghaith into the United States for civilian prosecution makes little sense and reveals, yet again, a stubborn refusal to avoid holding additional terrorists at the secure facility at Guantanamo Bay despite the circumstances," McConnell said.

It echoed an earlier clash over attempts by the administration to try alleged 9/11 mastermind Khalid Sheikh Mohammed in New York. Faced with an outcry and warnings that it posed a security risk to the US's most populous city, Obama relented and moved the case back to Guantanamo.

Abu Ghaith was arrested on 28 February and was transferred to US soil the following day. He was reportedly picked up in Turkey after entering the country from Iran. Local authorities passed on information to US authorities and a handover of Abu Ghaith reportedly took place in Jordan.

In court Monday, his lawyers indicated they would apply for a motion to strike from the record a post-arrest statement from the alleged al-Qaida spokesman.

That motion – along with the one to have the case moved – will be put before the court in May.

During a discussion on trial scheduling, Kaplan suggested that jury selection could take place either in September or January next year. But defence lawyers pointed out that due to the furloughing of federal employees, the earlier date could be impossible.

"It would be very hard for us to be ready by September," Cohen told the court.

Kaplan said he was stunned.

"The irony – that is not exactly the right word – is it is extremely troublesome to contemplate the possibility of a case of this nature being delayed because of sequestration," he said.

Cohen later explained to reporters that lawyers at the Federal Defenders of New York have been told they must take 27 days off by the end of September as a result of the sequestration.

Throughout Monday's hearing Abu Ghaith remained silent. Dressed in a blue prison smock, he was led into the courtroom in handcuffs. He listened to proceedings through a translator.