India's top court Wednesday ordered the government to establish special tribunals to fast-track the trials of lawmakers charged with criminal offences, saying it must crack down on lawlessness in politics.

The government, which told the Supreme Court it was not against the idea, has six weeks to submit a plan for expediting cases against politicians through India's notoriously sluggish legal system.

Judges in New Delhi said it was imperative these outstanding prosecutions were resolved within the year.

‘We will not let you wash your hands (of the responsibility),’ Justice Ranjan Gogoi told lawyers for the central government.

The government must update the court about the status of unresolved criminal cases dating back to 2014 involving more than 1,500 politicians, and any new charges registered since then, Justice Gogoi said.

Prime Minister Narendra Modi, who was elected in 2014, has vowed to cleanse parliament of criminals, where a record number of elected representatives face charges.

One in three MPs who contested the 2014 general election were facing charges including murder and rape, said a report by the Association for Democratic Reform.

Candidates with a criminal record were almost three times as likely to be elected than those without, the government watchdog found.

Many politicians can seek re-election while awaiting trial, which can take years in India's overloaded criminal justice system, spurring calls for speedier courts to try lawmakers.

India's justice system is notoriously slow, but the country set up fast-track courts to try rape cases following a national outcry over the 2012 gang rape of a young woman on a bus in New Delhi.

Political reform advocates also want lawmakers with criminal records to be banned from ever contesting office again, a proposal supported by India's Election Commission and under consideration by the government.

‘If the politician is serving when he's convicted, he shouldn't be allowed to contest again,’ Vikas Singh, an advocate who has petitioned the Supreme Court for the lifetime ban, told AFP.

The case returns to the Supreme Court on December 13.