LONDON, Aug 10: This is not the first time Naramalli Sivaprasad, 67, has used costumes to register dissent.
His costume choices in the past include a mythological character, a Hindu god, a spiritual guru and a woman.
"What I am doing will grab attention quickly. It will make people think," he told BBC Telugu's Ravi Shankar.
A former actor, Mr Sivaprasad is an MP from the southern state of Andhra Pradesh. He belongs to the state's ruling Telugu Desam Party (TDP).
But his controversial choice of costume on this occasion has caused some shock.
One Twitter user said: "An elected MP attended parliament dressed as Hitler - the man who sent millions to their deaths in gas chambers and war. It only caused amusement. Any surprise then that hate is so normalised in India."
Mr Sivaprasad said he was protesting against the federal government's refusal to grant "special category" to Andhra Pradesh. The status would ensure more funds for development.
The TDP was a member of Mr Modi's ruling federal alliance but it withdrew earlier this year over the issue.All Mr Sivaprasad's costumes have been inspired by what he sees as unfair treatment of his state by the federal government.
When asked why he chose to dress as Hitler, Mr Sivaprasad said: "I have a reason for everything I do. Hitler never sought anyone's counsel and he did not work for the welfare of people."
He seemed to suggest that this was similar to what Mr Modi was doing, saying that while Mr Modi had won the election in 2014 amid "great expectations and hopes", his government was not living up to expectations.Nazi imagery is not uncommon in India, where Adolf Hitler is admired by some young people and his autobiography, Mein Kampf, is popular. Earlier this year the Nazi dictator was featured in a children's book about inspiring leaders, sparking a complaint from US-based Jewish human rights organisation the Simon Wiesenthal Center.People reacted with both amusement and shock on social media to Mr Sivaprasad's latest costume.Some dismissed it as a "dramatic stunt" while others wondered how he could be "so casual" about one of history's biggest mass murderers.
People were also tweeting photos of other such "protests" by Mr Sivaprasad in the past - he has donned at least 15 such costumes by one user's count.
He has appeared in parliament dressed as Hindu god Rama, popular spiritual guru Satya Sai Baba and other famous characters from Hindu mythology.
In March, he arrived at parliament house in Delhi wearing a sari.
"I am an artiste. An artiste can use more creative methods of protest," he told BBC Telugu, when asked to explain why fancy dress costumes are his preferred mode of protest.