The WikiLeaks founder, Julian Assange, will try to win his release from prison today afternoon, a week after being held on remand after Sweden requested his arrest over allegations that he sexually assaulted two women. Even if the judge at Westminster magistrates court in London grants Assange bail, he could still be held.

The Crown Prosecution Service, which will represent the Swedish authorities in the UK court, has the right to appeal against any bail decision. Usually the suspect would be held in custody until an appeal hearing anyway.

Raj Joshi, a former head of the European and international division at the CPS, and an expert on extradition, said: “If they feel they have grounds for opposing bail, they would be duty bound to appeal that. He’ll be held pending the appeal, and until it is decided. That hearing is usually held within 48 hours.”

The chances of Assange going underground, given that his face was “plastered all around the world”, were low, he added. “With a number of conditions, such as, maybe, a tag, it would be difficult to see why bail would not be granted.”

The decision on whether to oppose bail will be made by the Swedish authorities, with Britain’s CPS merely representing their interests at tomorrow’s hearing. Speculation that the US could lodge an extradition request continued over the weekend, but it is regarded as highly unlikely that any such request would be lodged today afternoon.

Lady Kennedy, who has extensive experience in human rights, has joined Assange’s defence team.

His case has stirred fresh controversy about European arrest warrants, which the Swedish authorities would use for his extradition.

Lady Ludford MEP, the Liberal Democrat European justice and human rights spokeswoman, claimed the arrest warrant system, which she said she supported, was being used by Sweden to carry out a fishing expedition. Sweden had yet to formally charge Assange with any offence.

In a letter to the Guardian, Ludford wrote that past cases showed that it was “not a legitimate purpose for an EAW to be used to conduct an investigation to see whether that person should be prosecuted”. She added: “Normal cross-border cooperation on collection of evidence or interrogation of suspects called ‘mutual legal assistance’, using for example video-conferencing or a summons for temporary transfer of a suspect, should be used when more appropriate. “I urge the UK courts to refuse to allow the Assange EAW to be a fishing expedition without a pending actual prosecution. EU rules should be properly respected so that the integrity of the European arrest warrant process is protected.”

Ahead of the case, lawyers today visited Assange in Wandsworth prison, south London, where the 39-year-old is being held in the segregation unit.

Assange’s mother Christine is understood to have flown from Queensland, Australia to London to attend his bail hearing afternoon. It also emerged last night that the film-maker, Michael Moore, has offered to post security for the WikiLeaks founder.

Assange’s lawyer Mark Stephens visited him in Wandsworth prison yesterday afternoon and said his client was being held under harsher conditions than last week. He claimed Assange was being confined to his cell for all but half an hour a day, and denied association with others prisoners, access to the library or TV.

“He’s subject to the most ridiculous censorship,” Stephens said. “Time magazine sent him a copy of the magazine with him on the cover and they censored it not just by ripping off the cover but by destroying the whole magazine.”

Stephens also claimed a number of letters to Assange from media organisations have not reached him. He said Assange was under 24-hour video surveillance and had complained that a tooth which broke off while he was eating had later been stolen from his cell.

Stephens said Assange’s UK legal team had still not seen the prosecution evidence against him. “His Swedish lawyers have some of the material but not all and it’s in Swedish so we can’t take proper instructions.”

The decision by the district judge Howard Riddle to remand Assange into custody was made despite the film director Ken Loach, the journalist John Pilger, and the socialite Jemima Khan, offering sureties for him totalling £180,000. The judge had concluded that because of the “serious” nature of the allegations against Assange, his “comparatively weak community ties” in the UK, and the fact it was believed he had the financial means and the ability to abscond, there was a substantial risk he would fail to surrender to the courts.