In a major setback to the Arvind Kejriwal-led Aam Aadmi Party (AAP) before the Delhi Assembly polls, senior party leaders MS Dhir and Harish Khanna on Friday joined the Bharatiya Janata Party (BJP).

Dhir, the former speaker of Delhi Assembly, said that he would look to serve the BJP to the best of his abilities.

"I will serve the BJP to the best of my abilities. By joining the BJP, in a way, I have returned to my home," he told the media here.

"Nobody from the Aam Aadmi Party has contacted me. If they do get in touch with me, I will tell them that seeing Prime Minister Narendra Modi's mantra for development, they too should join the BJP," he added.

Meanwhile, Khanna, the MLA from North Delhi's Timarpur area, had earlier this month refused to stand for the elections, citing anguish over the way the AAP had taken some decisions. However, he was still a member of the party before joining the BJP on Friday.

With the Union Cabinet recommending the dissolution of the Delhi Assembly and setting the stage for fresh elections in the days to come, political parties have begun finalizing their poll campaign strategy to grab power here.

President's rule was imposed in Delhi since February after Kejriwal resigned as the Chief Minister after remaining in power for 49 days.