But the criticisms leveled against Modi's government were not solely about the lions' appearance.

Some opponents saw Modi's involvement in Monday's inauguration ceremony -- especially in the absence of opposition leaders -- as breaching the constitution's separation of legislative and executive powers. Others considered Modi's prayer offering as inappropriate, given that he was opening a secular national building.

"As head of (India's government), @PMOIndia shouldn't have unveiled the national emblem atop new parliament building," tweeted Asaduddin Owaisi, a member of parliament and leader of the All India Majlis-e-Ittehadul Muslimeen political party. The move "violated all constitutional norms," he added.

The new parliament, announced less than three years ago, is expected to open in October, just months after the upcoming 75th anniversary of Indian independence. The building forms part of the Central Vista Redevelopment Project, a $1.8 billion overhaul of New Delhi's historic administrative center that has attracted criticism from politicians, architects and heritage experts over the cost and timing of the works.

Supporters of the project have argued that the current parliament is unfit for purpose. The building's architect, Bimal Patel, told CNN last year: "We need to improve the technology, we need space for dining, we need to create toilets, we need to create storage space, and office and administration space -- it's very clear that it can't be done in the space available."