Arvind Kejriwal, his deputy Manish Sisodia and Bhagwant Mann during rally in Barnala.

Aam Aadmi Party (AAP) lawmaker Bhagwant Mann, who has often been accused of drunken behavior in public, revealed on Sunday that he had given up drinking on his mother's advice. And promptly got a back-slapping endorsement from party chief Arvind Kejriwal, who called it a "big sacrifice".

"My political opponents often level accusations against me, saying 'Bhagwant Mann drinks too much and is drunk day and night'. Brothers, it always pained me when I saw old videos of myself on social media where I was being defamed," Mr Mann said at a rally.

He said he had given up drinking as of January 1 and hoped to stay firm on his resolve for the rest of his life.

"I admit I used to take liquor occasionally. But my political opponents maligned me. Today my mother is here. She had told me that people maligned me excessively on television and then asked me to stop taking liquor. Now they cannot defame me," said Mr Mann, who is expected to contest the upcoming national election from his seat Sangrur in Punjab.

In 2016, suspended AAP lawmaker Harinder Singh Khalsa had complained against Mr Mann to Lok Sabha Speaker Sumitra Mahajan, requesting her to change his seat in Parliament as Mr Mann, who sat next to him, reeked of alcohol.

Mr Kejriwal praised Mr Mann for giving up drinking, saying it was "no small commitment".

"Friends, Bhagwant Mann has won my heart. Not only mine, he also won the hearts of the entire Punjab. Every leader should be like him and be ready to make any kind of sacrifice for the people. It is not a small thing to make such a big commitment. He says he will not touch liquor. It is a very big thing," said Mr Kejriwal.

Mr Kejriwal said Mr Mann, who was a stand-up comic, gave up his thriving career to serve the people of Punjab.

"Today Punjab is sinking because of drugs. In the last Punjab elections, Mr Mann fought against Sukhbir Singh Badal from Jalalabad seat because he felt at that time Sukhbir was the biggest guilty for the situation Punjab was in. Today, Sukhbir Badal is responsible for drugs in Punjab," alleged Mr Kejriwal.

Mr Kejriwal asked how many people were ready to shun liquor for the sake of people.

Mr Mann had also claimed in his speech that nobody could accuse him of embezzling even a single penny. He also lashed out at the Akali Dal and Congress.

Mr Kejriwal later told reporters that AAP would contest all 13 Lok Sabha seats in Punjab. "We will contest all 13 seats in Punjab. There will be no alliance with the Congress in Delhi or in Punjab. People were earlier fed up with the Akali Dal and now with the Congress as they failed to honour any poll promise. We will carry out the same work in Punjab as we have done in Delhi," said Mr Kejriwal.