Prime Minister Narendra Modi is due to inaugurate India's new parliament building amid a boycott of the ceremony by 20 opposition parties.

Ceremonies leading up to a formal inauguration began at 7.30am on Sunday with a prayer.

Mr Modi also installed a historically significant gold sceptre called sengol in the house chamber.

He has unveiled a plaque dedicating the new parliament to the country and is expected to make a speech later.

But MPs from several major opposition parties are not participating in the event.

Last week, 20 parties - including the main opposition Congress - had announced their "collective decision" to boycott the inauguration ceremony.

They had criticised the government for not asking President Droupadi Murmu, the parliament's highest constitutional authority, to open the new building. They also denounced the decision to hold the event on the birth anniversary of Hindutva ideologue VD Savarkar. Opposition parties consider Savarkar as a divisive figure, while the ruling Bharatiya Janata Party (BJP) hails him as a hero.

The BJP has called the boycott a "disrespect of democracy".

On Sunday, Mr Modi will also unveil a new 75-rupee coin to commemorate the event and serve as a tribute to 75 years of India's independence.

The new parliament building is part of the government's ambitious project to develop the Central Vista power corridor in capital Delhi.

Built in front of the British-era parliament, the new four-storey parliament building - built at an estimated cost of 9.7bn rupees ($117.1m, £94.2m) - has increased seating capacity, with 1,272 seats across two chambers.

The Lok Sabha chamber, which will seat the lower house of the parliament, is designed in the likeness of a peacock, India's national bird. The Rajya Sabha chamber, which will seat the lower house, is designed to resemble the lotus, India's national flower.

The current parliament building is expected to be converted into a museum.

The government has said that the new parliament was necessary as the older building was "showing signs of distress and over utilization".

But its construction, along with that of the Central Vista project, during the pandemic had received criticism from many opposition politicians, environmentalists and civil society groups. They decried its cost, its construction during the pandemic and alleged that the government had not consulted other lawmakers and the public.

The Congress had also stayed away from the foundation stone-laying event of the new parliament in 2020.

Last week, several opposition leaders criticised the government's announcement that Mr Modi would formally open the building, along with Lok Sabha speaker Om Birla.

Commentators have said that the row reflects a fractious milieu where India's ruling party and the opposition are unable to reach an agreement on most issues.

"Both sides need to find a way out of the separate corners they have backed themselves into. They must do so because history will not forgive them if they won't," The Indian Express newspaper had argued in an editorial. "They must do so, for the sake of the people, and for the people's parliament."

As the new parliament is inaugurated, it may also witness protests by India's top wrestlers outside the building.

The wrestlers, including Olympic medallists, have been on a month-long protest at Jantar Mantar, a heritage site in the capital Delhi, demanding the resignation and arrest of their wrestling federation president, Brij Bhushan Singh

Singh, an influential lawmaker and politician from BJP, is accused of sexual abuse and harassment of female wrestlers - allegations he denies.

Delhi police officials have told reporters that security has been tightened in the city and its borders to ensure that the protests don't "disrupt" the parliament's inauguration.

"Any attempt to create disturbance in the inauguration of the new Parliament building will be dealt with very politely and firmly. I request our respected athletes not to do any such thing today," said Dependra Pathak, special commissioner, Delhi Police.

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