The high-profile case against Basuki Tjahaja Purnama - the first Christian to govern the capital in more than 50 years - has captivated attention in Indonesia, and fanned concerns about hardliners pushing their agenda in the nation of 255 million.
Purnama, known for his outspoken style, ignited a firestorm of criticism when he quoted a verse from the Islamic holy text in September.
The governor apologised but his remarks angered Muslims - both moderate and conservative - who marched against him in the largest rallies seen in Indonesia in years.
In a teary, nationally televised defence last week, Purnama denied ever intending to offend his Muslim countrymen and asked the judges to dismiss the case.
Prosecutors argue he insulted Muslims by claiming his political opponents were using the Koran to sway voters against him.
Purnama's lawyers claim proceedings are being rushed and the judges subject to public pressure.
Outside the courthouse, dozens of hardline Islamists chanted "God is Great" and waved banners demanding Purnama be jailed, while supporters called for his release.
Almost all blasphemy cases in Indonesia have resulted in convictions.
Purnama, better known by his nickname Ahok, faces a maximum five-year prison sentence if found guilty.
The laws have seen Muslims from sects deemed deviant put behind bars, and even atheists have been handed jail sentences for falling foul of the provisions.
Rights groups claim the laws are used to persecute minorities and fear the highly public case against Purnama is eroding Indonesia's reputation for tolerance and diversity.
Long the favourite to win re-election in February, Purnama has watched his lead slip as the case against him has dragged on.
He is running against two Muslim candidates for the governorship of Indonesia's largest city.
