Manvendra Singh, the son of BJP veteran Jaswant Singh, is set to join the Congress tomorrow at its chief Rahul Gandhi's home. It was seen by many as a matter of time after the 54-year-old Rajasthan lawmaker quit the BJP on September 22, describing his resentment with the party at a public rally with the phrase:Kamal Ka Phool, Hamaari Bhool (lotus (BJP) was my mistake).