India's main opposition leader Rahul Gandhi has returned to the streets of central New Delhi, leading dozens of members of parliament in renewed demands for the resignation of Chief Election Commissioner Gyanesh Kumar.

Gandhi, heir to India's most influential political dynasty, is seeking to transform a summer youth uprising into a broader challenge to Prime Minister Narendra Modi's decade-long grip on Indian politics.

At a press briefing on Monday, Gandhi said the Modi government had put the capital "in jail."

The youth-led "Cockroach" movement, which forced out the education minister in July, has also threatened to protest on Tuesday if it is not permitted to rally at Jantar Mantar in central Delhi, the focal point of this summer's demonstrations.

Joining Gandhi's Congress party, other opposition forces, and the Cockroach Janta Party (CJP) are thousands of students from left-wing organisations.

As the government braces for further unrest, security forces have been detaining thousands of students each day. Allegations of custodial violence have cast a climate of fear over the capital.

India's Election Commission, a supposedly autonomous body tasked with overseeing the world's largest electorate, has come under sharp criticism following revelations that its chief, Gyanesh Kumar, frequently overruled concerns raised by the other two election commissioners regarding the integrity of changes to the voter database.

For months, opposition parties have argued that the commission is compromised and is sabotaging elections for the electoral benefit of Modi's Bharatiya Janata Party (BJP). The BJP denies the allegations.

Since June last year, the commission has been revising and updating statewide voter lists. More than 130 million names have since been removed. Critics say the deletions have disproportionately deprived minorities and other vulnerable groups of the right to vote.

Gandhi has called for the Chief Election Commissioner to be tried for treason. "We will not spare you," he said, referring to Kumar, at his Monday press briefing.

Opposition politicians allege that protest rallies, including those led by Gandhi, have been met with violent force, as seen in videos showing participants being detained.

"[The protesters] came with love in their hearts, not hatred or anger," Gandhi said, referring to a protest on Saturday. "They were beaten, both by cops and BJP goons."

"Narendra Modi cannot silence India's voice. These cowards cannot intimidate us. They will have to step aside," he wrote on X, calling on people from all walks of life to join Monday's protest.

Analysts say the current situation differs markedly from the summer protests, when CJP-led demonstrators focused their demands on the resignation of then-Education Minister Dharmendra Pradhan.

Political analyst Asim Ali told sources that the broader opposition mobilisation would not stop, but that the Modi government was unlikely to back down.

"The crackdown this time on students is making it apparent that it would be tougher for young protesters this time, and students can't get beaten up and dragged violently daily," he said. "Going forward, the opposition parties stand to be the front face of the protests, and they need to lead from the front."

Ali drew a historical parallel, noting that since 1975, when then-Prime Minister Indira Gandhi imposed a state of national emergency suspending civil liberties, India had seen "more civil politics grow into mainstream, where opposition parties were allowed space." He added that after five decades, "those democratic gains have vanished -- and there are no constraints on this government by independent institutions."

Political analyst Rasheed Kidwai said he had witnessed New Delhi at the centre of "several big opposition political rallies, held in areas near the parliament, hosting hundreds of thousands of people," during which police did not interfere -- in contrast to the crackdowns seen this year.

Kidwai said the violent detention of members of parliament was particularly worrying. "We are seeing a big change from when politicians were more tolerant of dissent," he added.