Former Pakistani Prime Minister Imran Khan's lawyers are attempting to launch legal challenges against his three-year prison sentence for corruption, which could bar him from politics and prevent him from contesting national elections. Khan was arrested on Saturday and taken to Attock Jail, where he is being held in harsh conditions. His lawyers have been denied access to him so far, but they are filing petitions in Islamabad and Lahore High Courts to challenge his conviction and request better prison facilities. Khan's arrest has sparked protests, but his popularity has been diminished due to a crackdown by authorities and the muzzling of the press. Khan's supporters have accused Washington, the government of Prime Minister Shehbaz Sharif, and the Pakistani military of conspiring against him. The former prime minister's lawyers are also requesting that he be allowed to see his wife and personal physician. The prison term started on Saturday, but it is unclear if Khan will spend the entire three years in Attock Jail. Authorities have tightened security around the prison and instructed locals not to allow media onto their roofs to prevent photographs and videos from leaking. Khan has previously been arrested in May on corruption charges, which led to violent protests across the country. The Supreme Court ordered his release, ruling that his arrest was illegal. However, his recent conviction could disqualify him from holding or running for public office, and parliament may be dissolved ahead of the natural end of its term to hold an election. There is speculation that the election could be delayed due to the release of the country's latest census data.