Indian opposition events united on Sunday to protest in opposition to the arrest of a distinguished chief weeks earlier than a nationwide election, accusing the prime minister, Narendra Modi, and his celebration of rigging the vote and harassing them with giant tax calls for.

“Narendra Modi is trying match-fixing in this election,” the chief of the opposition Congress celebration, Rahul Gandhi, instructed a rally in New Delhi, as the gang chanted “shame”.

Delhi’s chief minister, Arvind Kejriwal – a staunch critic of Modi, an anti-corruption crusader and a high-profile chief of the INDIA opposition alliance – was arrested on 21 March for alleged graft over granting liquor licences, lower than a month earlier than voting begins in a basic election broadly anticipated to solidify Modi’s mandate with a uncommon third time period.

Kejriwal’s Aam Aadmi celebration says the case in opposition to him is fabricated and politically motivated. Modi’s authorities and his Bharatiya Janata celebration (BJP) deny political interference and say legislation enforcement businesses are doing their job.

Gandhi mentioned: “If the BJP wins this match-fixing election and changes the constitution, it will light the country on fire. This is not an ordinary election. This election is to save the country, protect our constitution.“

Gandhi’s Congress party ruled India for more than two-thirds of the time since the country gained independence from Britain in 1947, but has struggled since Modi swept to power a decade ago.

Sharing the stage with Gandhi during the rally at the popular Ramlila Maidan gathering site in New Delhi were opposition leaders including regional party heads who have overcome their differences regarding which party would contest which seats.

Sunita Kejriwal, the wife of Kejriwal, told the rally: “This fascism will not work in India. We will fight and we will win.”

Modi mentioned his battle in opposition to corruption had rattled the opposition. He mentioned this election was a battle between his celebration and its allies, who need to take away the corrupt, and an opposition that desires to guard the corrupt.

“Big corrupt people are behind bars and even the supreme court is not giving them bail,” Modi mentioned in a rally to launch his election marketing campaign within the populous northern state of Uttar Pradesh on Sunday.

Congress – in addition to fighting detentions and raids by India’s monetary crime-fighting company – says it’s battling “tax terrorism” amid giant tax calls for by the federal government and the freezing of a few of its financial institution accounts, which it says are makes an attempt to financially cripple the celebration.

Critics say Modi and his celebration have weaponised investigative businesses and tax authorities to cull political opponents and scale back the probabilities of a good election, an accusation the BJP denies.