Julian Assange's lawyers have complained that they've not been given sufficient time time whilst inside Belmarsh Prison as he appears in person before magistrates court today, backed by dozens of supporters.

Speaking at Westminster Magistrates Court, Assange's lawyer Gareth Peirce said there had been a "breach of a defendant's rights," and was duly granted extra time with her client by District Judge Vanessa Baraitser duly.

Assange, 48, appeared at the court wearing a black jacket and grey jumper, some stubble and his grey hair swept back, and saluted his supporters in the public gallery as he was brought into court.

The WikiLeaks founder is currently being held in the high security prison HMP Belmarsh, awaiting the outcome of an extradition request by the US where he faces 18 charges, including conspiring to hack into a Pentagon computer.

Whilst the Australian only spoke briefly to confirm some details, a group of his supporters, including rapper M.I.A. staged a protest ourside the court and packed out the public gallery.

Holding banners demanding Assange's release, supporters queued for 30 minutes to get into the building due to the clamour for a seat. Around 40 people were allowed inside the packed public gallery, including the rapper, real name Mathangi Arulpragasam.

Inside, Ms Peirce told the court there had been a lack of contact time to speak to her client at Belmarsh, something which threatened to delay the serving of evidence ahead of the trial, she said.

She said: "We have pushed Belmarsh in every way - it is a breach of a defendant's rights."

The district judge agreed to adjourn the hearing until the end of the day, in order to allow Assange and Ms Peirce a chance to sign off papers and go over their case together at court, rather than have Assange sent back to prison.

About 15 protesters maintained a vigil outside court, chanting Assange's name and calling for him to be freed.

Speaking outside the court, the rapper M.I.A told the PA News Agency: "I think it was important to follow this case.

"I am off to get a medal at Buckingham Palace tomorrow (an MBE for services to music) and I think today is just as important.

"To give somebody an hour to put their case together is not right."

Australian Assange is accused of working with former US army intelligence analyst Chelsea Manning to leak hundreds of thousands of classified documents.

Assange was jailed for 50 weeks in May last year for breaching his bail conditions, after going into hiding in the Ecuadorian embassy in London to avoid extradition to Sweden over sex offence allegations, which he has always denied.

Swedish authorities later dropped the rape investigation.

He had been in custody since he was dramatically removed from the embassy building in April.

Assange's full extradition hearing is scheduled for February 24 at Woolwich Crown Court.