Police stopped around 300 Opposition MPs from marching towards the Election Commission on a humid Parliament Street around noon on Monday and later detained about 30 of them at a police station.

Congress MP Sanjana Jatav and Trinamool MPs Mahua Moitra and Mitali Bag fainted while courting detention.

The Election Commission (EC) had agreed to meet only 30 MPs. The police, who stopped the MPs near Transport Bhavan, about 1km from the commission, said they had orders to allow them to move further only if the poll panel asked them to.

Several MPs — including Moitra, Bag and their Trinamool colleague Sushmita Dev, Congress member S. Jothimani and the Samajwadi Party’s Akhilesh Yadav — climbed over the barricades.

Later, about 30 MPs, including the leaders of the Opposition in both Houses, were taken in buses to the Parliament Street police station where they were detained briefly. The marchers included MPs from the INDIA bloc and the Aam Aadmi Party.

Trinamool members Pratima Mondal, Mamata Thakur and Dola Sen, who went directly to the commission without participating in the march, weren’t allowed to enter Nirvachan Sadan. They shouted slogans at the gates until the police removed them.

Rahul Gandhi told reporters from the window of a police van: “They (commission) actually cannot talk (has no reply). The truth is in front of the country…. This fight is to save the Constitution. This fight is for One Man, One Vote. We want a clean, pure voters list.”

Jatav and Bag had fainted while waiting to board a police van. Jatav was taken to Ram Manohar Lohia Hospital, and Bag received treatment at the medical centre in Parliament annexe. They were soon discharged.

Moitra fainted inside the police van, where Rahul and others came to her aid. She had recovered by the time the van reached the police station.

Moitra said in a video message: “The police told us that they were taking us to the EC but we were taken to different police stations instead.”

Through their protest on Monday, the MPs chanted slogans and held up placards in the languages of the states they were elected from.

Those detained signed a letter to the station house officer calling their detention “undemocratic and illegal breach of our right to protest as well as attend Parliament”.

Parliament convened at 2pm, and the MPs left the police station around 3pm. Copies of the letter were marked to the presiding officers of both Houses of Parliament.

An INDIA source said they would discuss bringing a privilege notice against the police at the alliance’s meetingon Tuesday.

This was the latest round in the confrontation between the poll panel and the Opposition since chief election commissioner (CEC) Gyanesh Kumar took over in February.

The big flashpoints have been the document-based special intensive revision (SIR) of Bihar’s electoral rolls, a pilot for a nationwide rollout that includes a test of citizenship, and Rahul’s claim of more than 1 lakh “fake voters” in a Bengaluru Assembly constituency.

The poll panel has pushed through with the Bihar revision despite repeated complaints and amid litigation against it in theSupreme Court.

It has put the onus on Rahul to prove his allegation of fake voters in Bengaluru and in other states where the Congress has alleged the manipulation of voter enrolment and deletions.

In X posts, the EC on Monday “fact-checked” similar allegations made in tweets by the Congress and Rahul. “The Statements made are factually Incorrect,” it posted.

The poll panel also posted links to videos of district-level representatives of the Opposition parties in Bihar receiving copies of the draft rolls, as well as lists of the names excluded from it.

The Opposition parties have demanded digitally readable rolls — as opposed to scanned copies of rolls currently mandated under law — and the reasons for the exclusion of each voter. The poll panel says it has provided the scanned copies and reasons but the INDIA partieshave denied it.

A commission source shared copies of the poll panel’s communication with Congress communications head and MP Jairam Ramesh.

Replying to Ramesh’s request on Sunday for an appointment to Opposition parties to meet the commission, the poll panel had asked him the same day to give the names of 30 people “due to limitation of space”.

Ramesh had acknowledged their reply, saying: “Many thanks.”

However, the Opposition went ahead with the march. Previous CECs had met large delegations of MPs.

Moitra, in her video message, said: “Our demands are for an FIR against Rajiv Kumar (who was the CEC during last year’s Lok Sabha polls) for malpractices, digitisation of the voter list, and stopping the SIR…. We will not give the names of our BLA-2 as it will go straight tothe BJP.”

Each political party is free to nominate up to two booth-level agents (BLAs) to coordinate with the booth-level officer — a government official in charge of updating the electoral rolls in a polling station area.

This is optional, and in Bihar, no party has been able to nominate even a single BLA for every booth.