New Delhi/IBNS: A day after quitting the Aam Aadmi Party (BJP), former Delhi minister Kailash Gahlot joined the Bharatiya Janata Party (BJP) on Monday.

Gahlot joined the BJP a few months ahead of the Delhi assembly elections.

Gahlot was heading key portfolios in the Delhi government, including Home, Transport, IT and Women and Child Development.

In his resignation letter addressed to AAP convener Arvind Kejriwal, Gahlot said he was facing "grave challenges" within the party.

"Political ambitions have overtaken our commitment towards people, leaving many promises unfulfilled. Take for example the Yamuna, which we had promised to transform into a clean river, but never got around to doing it. Now the Yamuna River is perhaps even more polluted than ever before," he said.

Taking an indirect dig at Kejriwal, he has referred to "many embarrassing and awkward controversies like the Sheeshmahal"- a term used by the BJP to refer to the Chief Minister's residence renovation during the AAP's supremo's term.

He has said such controversies "are now making everyone doubt whether we still believe in being the Aam Aadmi".

Gahlot alleged that AAP has been "fighting for its own political agenda" and this has "severely crippled our ability to even deliver basic services to the people of Delhi".

"It is now obvious that real progress for Delhi cannot happen if the Delhi Government spends majority of its time fighting with the Centre," he said.