India's major opposition parties Sunday boycotted the inauguration of a new parliament building by Prime Minister Narendra Modi in a rare show of unity against his Hindu nationalist ruling party, which has spent nine years in power and is seeking a third term in general elections next year.

Modi inaugurated the new parliament in the capital of New Delhi by offering prayers as Hindu priests chanted religious hymns at the start of the ceremony. Opposition parties criticized the event saying the prime minister had sidelined President Droupadi Murmu, who has only ceremonial powers but is the head of state and highest constitutional authority.

"May this iconic building be a cradle of empowerment, igniting dreams and nurturing them into reality," Modi tweeted shortly after the inauguration.

Senior ministers from Modi's party and leaders from its alliance partners attended the inauguration but at least 19 opposition parties skipped the event, which coincided with the birth anniversary of a Hindu nationalism ideologue.

Opposition parties said in a statement Wednesday that Modi's "decision to inaugurate the building by himself" was "a grave insult" to India's democracy, adding that the ruling government had "disqualified, suspended and muted" opposition lawmakers while passing "controversial legislation" with little debate.

"When the soul of democracy has been sucked out from the parliament, we find no value in a new building," the parties said.

India's powerful Home Minister Amit Shah said the opposition had politicized the event and other leaders from Modi's party said the boycott is "an insult to the prime minister."

The new triangular-shaped building — built at an estimated cost of $120 million — is part of a $2.8 billion revamp of British-era offices and residences in central New Delhi that will also include blocks of buildings to house government ministries and departments, and Modi's new private residence. The entire project, called the "Central Vista," is spread over 3.2 kilometers (1.9 miles).

The project was announced in 2019 and Modi laid its foundation a year later in December 2020.

The plan has drawn intense criticism from opposition politicians, architects and heritage experts, many of whom have called it environmentally irresponsible, a threat to cultural heritage and too expensive.

Outrage grew in 2021 when at least 12 opposition parties questioned the project's timing, saying it was built as the country faced a devastating surge in coronavirus cases. They branded the revamp as Modi's "vanity project" and said its construction was prioritized over the loss of lives and livelihoods during the pandemic.

A year earlier, a group of 60 former civil servants wrote an open letter to Modi to highlight the architectural value of the old parliament building and said the new plan would "irrevocably" destroy the area's cultural heritage.

Modi's government has said the revamp was necessary because the older building was "showing signs of distress and over utilization" and that the new design "combines the country's heritage and traditions."

The newly inaugurated building sits just across from India's old parliament, a circular structure designed by British architects in the early 20th century. The new four-story building has a total of 1,272 seats in two chambers, almost 500 more than the old building.

The old parliament will be converted into a museum.

During the televised ceremony Sunday, Modi prostrated before a royal golden scepter that his Bharatiya Janata Party says symbolized the transfer of power when it was gifted to the country's first prime minister on the eve of India's independence from Britain in 1947. Dozens of Hindu priests followed Modi inside the parliament, where he installed the scepter near the chair of the speaker.

Modi's critics and opposition leaders have questioned the scepter's historicity and said the emblem is appropriate to a monarchy, not a democracy.

The prime minister's supporters see the new parliament as his attempt to remake India's power corridor and disrupt the country's colonial legacy.

Last year, Modi inaugurated a revamped colonial avenue in the heart of New Delhi that is used for ceremonial military parades. The boulevard was earlier called "Rajpath," or Kingsway, but Modi's party changed it to "Kartavya Path," or road to duty, arguing the old name was a "symbol of slavery" that had "been erased forever."

Many such moves by Modi's ruling government have been met with strong criticism, but the controversy over the new parliament building has been the most fractious.

It comes just months after opposition leaders protested Congress leader Rahul Gandhi's disqualification from Parliament in a defamation case over remarks he made about Modi's surname.

Hours before the new parliament was opened, the Congress party's general secretary, Jairam Ramesh, criticized Modi again.

"A self-glorifying authoritarian Prime Minister with utter disdain for Parliamentary procedures, who rarely attends Parliament or engages in it, inaugurates the New Parliament building in 2023," he tweeted.

Barely a mile away from the ceremony, a heavy police presence overpowered about 100 protesting Indian wrestlers and their supporters, who have accused their federation president of sexual harassment and had planned to march to the new parliament building. Some of the protesters scuffled with police and were taken away in a bus.

The protesters have been staging demonstrations in New Delhi for nearly a month demanding the resignation and arrest of Wrestling Federation of India President Brij Bhushan Sharan Singh for allegedly sexually harassing young athletes.

Singh, who has denied the accusations, is a powerful lawmaker from Modi's party.