BSP president Mayawati on Thursday called the opposition parties' boycott of the inauguration of the new Parliament building by Prime Minister Narendra Modi "unfair" as she welcomed the forthcoming opening.

The Bahujan Samaj Party chief said she will not be attending the inauguration on May 28 due to some other commitments, even though she has received an invitation.

Nineteen opposition parties, including the Congress, Left, TMC, SP, and AAP, on Wednesday announced their boycott of the inauguration of the new Parliament building by Narendra Modi, saying they find no value in the new building when the "soul of democracy has been sucked out."

In a series of tweets Thursday, the BSP supremo said, "Be it the government of Congress party or now the BJP at the centre, the BSP has always supported them on issues related to the country and public interest. Rising above party politics and looking at it in this context, the party also supported the inauguration of the new building of the parliament on May 28, it is welcomed."

She also said the opposition parties' insistence that the new building be inaugurated by President Droupadi Murmu was "unfair."

"The government has made it, so it has the right to inaugurate it. It is also unfair to link this with the respect of a tribal woman. They should have thought of this while fielding a candidate against her instead of electing her unopposed," she said.

"I have received the invitation for the programme dedicated to the country, that is, the inauguration ceremony of the new parliament building for which I thank and extend my best wishes. But due to my pre-scheduled engagement regarding the continuous review meetings of the party, I will not be able to attend the function," she said.

The opposition parties in a joint statement on Wednesday had said that Modi's decision to inaugurate the new Parliament building himself was a "grave insult" and "direct assault" on Indian democracy.