Singh said he has known Sidhu since childhood and his "business" is that he wants to become the chief minister of Punjab. "There is no war of words with Navjot Singh Sidhu, if he is ambitious, it's fine, people have ambitions. I have known him since childhood, I have no difference of opinion with him," Singh said.
"He (Sidhu) probably wants to become CM and replace me, that is his business," Singh added.
This is not the first time that difference appeared between the two leaders.
Last week, Sidhu wife Navjot Kaur Sidhu alleged that it was Chief Minister Amarinder Singh who ensured that she was denied the Lok Sabha ticket from Amritsar. Sidhu backed her Kaur's accusation, saying she would "never lie".
Also, Sidhu had last year in Hyderabad said, "Rahul Gandhi is my captain Rahul Gandhi is the captain of the captain (Amarinder Singh) also." Amarinder Singh had earlier disapproved of Sidhu hugging Pakistan army chief during his visit to the neighbouring country.
Polling is being held on Sunday in all 13 Lok Sabha constituencies in Punjab in the seventh and final phase of general elections, with prominent faces including SAD chief Sukhbir Singh Badal and Union ministers Harsimrat Kaur Badal and Hardeep Puri in the fray.
On most of the 13 seats, the contest appears to be a direct fight between the Congress and the Shiromani Akali Dal-Bharatiya Janata Party alliance.
In 2014, the AAP and the SAD had won four seats each, the Congress three and the BJP two.