Speaking at a book-release function organised by the Public Union for Civil Liberties here, Justice Suresh questioned Modi's political origins as an RSS Pracharak.
"He is supporter of globalisation and communalisation. He cannot be a suitable candidate for PM's post," said Suresh, a noted human rights activists.
"After becoming Chief Minister, has he left the agenda of Ram-mandir, uniform civil code or of article 370?" Justice Suresh asked, referring to Modi's past as an RSS worker.
If Modi became the Prime Minister, would he remain loyal to the Indian Constitution rather than the RSS's "unconstitutional" agendas, Suresh asked.
Saying that when Adolf Hitler became Germany's chancellor it led to the World War, Suresh said, "he won't be surprised if Modi's ascension to the top post led to war with Pakistan or China."
He also alleged that Modi never visited European Union countries, fearing prosecution for the "genocide" (under EU constitution) during the 2002 riots.
'Sacchai Gujarat ki', a book by a city-based history professor Hemantkumar Shah, was released on this occasion.