Indian PM to lead day-long fast today in a tit-for-tat protest against opposition

India's Prime Minister Narendra Modi will lead a day-long fast on Thursday in a tit-for-tat protest against the opposition, whose leaders were caught feasting moments before they launched their own hunger strike.

The rival protests are part of growing showdown between Modi's ruling Bharatiya Janata Party (BJP) and Congress party ahead of a looming general election.

Both sides have suffered social media ridicule over their fasts.

Congress organised a five-hour hunger strike on Monday in a pre-emptive move against a BJP plan for its fast on Thursday.

But the party was left red-faced after photos of senior leaders tucking into chickpea curry served with a savoury dough circulated on social media right before the fast.

Congress faced sarcastic comments on Twitter, while the BJP called their protest a "joke".

With Modi set to lead Thursday's protest, the BJP has issued strict rules to its lawmakers, including a ban on eating at public places or being photographed noshing on treats before the fast.

It is also shooing away street food vendors from the protest venue in New Delhi, according to a newspaper report.

Congress has called the BJP's plans "a farce of a fast".

The BJP has said it will reject food for a day to show anger at the disruption of parliamentary business by Congress. Parliament sessions are regularly suspended amid unruly shouting matches.

Modi will fast to expose Congress's "undemocratic style of functioning and pursuing divisive politics and [an] anti-development agenda". Modi, a strictly observant Hindu and teetotal vegetarian, routinely fasts every year for the Navratri festival -- a nine-day ritual when he only takes liquids during daylight hours.

In a 2012 blog, Modi called his annual fast "an act of self-purification".