Singh met Congress president Rahul Gandhi before joining the party.
He said he was yet to take a decision on whether to join the Congress or not.
The BJP said that the decision will not have any impact on the party's prospects in western Rajasthan.
Manvendra Singh will take on the Rajasthan CM from Jhalrapatan constituency.
The Bharatiya Janata Party on Thursday sacked expelled party leader Jaswant Singh's son Manvendra Singh from its National Executive in the wake of reports that he was campaigning against the party's candidate Sonaram Chaoudhary in Barmer.
In the BJP veteran's home district, some feel he has been harmed by his party, while some think he never gave back to the place he belonged to, and then there are some who believe son Manvendra Singh will have a tough time living up to his name.
'The culture of the BJP has changed and the party too has changed with this new culture. 'The BJP is having bad political management, bad man management, personal management and inter-personal relationships.' 'Therefore, people like me are not in the BJP.'
Campaigning for May 13 elections in 96 Lok Sabha constituencies across 10 states and Union territories including all seats in Andhra Pradesh, where assembly elections are also being held concurrently, and Telangana concluded on Saturday evening.
Members from the Jayant Chaudhary's Rashtriya Lok Dal too were part of the group, their participation seen as another indication that the party is all set to switch sides from the SP to the ruling Bharatiya Janata Party ahead of the Lok Sabha elections.
However, Chief Minister Vasundhara Raje and her five cabinet colleagues have won their respective constituencies.
Vasundhara Raje may have had her faults but she is an unconventional and brave leader who deserves better, observes Aditi Phadnis.
Congress candidate Manvendra Singh, who recently crossed over from the BJP, will be facing off the Rajasthan chief minister in her political fortress of Jhalrapatan.
He said he is 'more than satisfied' with his long political career as a five-time Lok Sabha MP, three time Union minister and chief minister for 10 years.
The highest winning margin was registered by BJP candidate Subhash Chandra Baheria in Bhilwara who defeated Congress candidate Ram Pal Sharma with a margin of 6,12,000 votes.
Here's a list of the full first-time ministers in the second term of the Narendra Modi government.
Given the controversy over Uttar Pradesh's population control moves, Hemant Shivsaran/Rediff.com digs deep to find out how many children BJP MLAs in UP have.
Aggressive campaigning and the existing 'Modi wave' and a lack of will on part of the Congress has put the ruling Bharatiya Janata Party in Rajasthan far ahead of others. The party is comfortably placed in 21 out of the 25 seats, and they have been able to do this because of maintaining the same tempo that enabled them to defeat the Congress badly in December's assembly elections. P B Chandra reports