Union Minister M Veerappa Moily and N Dharam Singh (Congress), B S Yeddyurappa and D V Sadananda Gowda (BJP) and former Prime Minister and JDS supremo H D Deve Gowda are the main contenders in their constituencies.
Gowda's son H D Kumarswamy, who had headed the JDS-BJP coalition government in Karnataka for a little over 20 months till October 2007 and also a former Lok Sabha member, has indicated he may also throw in his hat in the ring after consulting party workers.
Warhorses Dharam Singh, Yeddyurappa and Deve Gowda appear to be on a strong turf in their respective constituencies while Moily and Sadanada Gowda may face a tough battle in Chikkaballapura and Bangalore North constituencies, respectively.
Moily is seeking re-election while Sadananda Gowda, also a former MP from Udupi-Chikkamagalur earlier, is now trying his luck from Bangalore North, held by his party.
Sadananda Gowda managed to secure the ticket for Bangalore North, for which there was another powerful contender former Minister R Ashok, who, however, pulled out of the race opting to remain in state politics.
Kumaraswamy may also enter the fray from Chikkaballapura to take on Moily. JDS had initially toyed with the idea of fielding his wife Anitha Kumaraswamy. Kumaraswamy is yet to take the final call.
The BJP has fielded senior state leader B N Bachche Gowda for this seat. Moily had served as Karnataka Chief Minister from 1992 to 1994.
Sadananda Gowda may also face a tough challenge in Bangalore North as the local BJP leaders were against his candidature since he hailed from state's coastal belt.
Gowda, who succeeded Yeddyurappa as Chief Minister surviving only for a short term before making way for Jagadish Shettar, is striving to get into the thick of national politics once again.
Yeddyurappa is contesting from Shimoga, his home district, and is pitted against JDS' Geetha Shivaraj Kumar.
This is the second time Yeddyurappa is seeking entry to Parliament after having failed in his first attempt earlier.
Shimoga was represented in the current Lok Sabha by his son B Y Raghavendra.
The Lingayat strongman is hoping to benefit from the family feud of former Chief Minister late S Bangarappa, who was an influential leader in his home district of Shimoga.
Bangarappa's daughter and wife of leading Kannada actor Shivarajkumar, Geetha Shivarajkumar is Yeddyurappa's main rival. Her brother Kumar Bangarappa, who has been denied the Congress ticket, has been piling pressure on the party to field him, though the official candidate has already submitted papers.
Deve Gowda, a five-time MP, is contesting from Hassan, a strong JDS bastion, which is dominated by Vokkaliga community to which he belongs. He seems to be sitting pretty given his stature vis-a-vis his rivals of BJP and Congress.
Dharam Singh, a sitting MP, who had headed a Congress-JDS coalition government in Karnataka for almost 20 months before it collapsed in February 2006, appears to be having an edge over his rivals.