"Rahul has got all those qualities and capabilities that are needed for a good Prime Minister", Singh, who has been working closely with the young leader, who turns 41 on June 19, told reporters.
Replying to a question, Singh said no leader on his own says that he wants to become the Prime Minister and all this depends upon the overall situation and circumstances.
Describing Rahul as "quite mature", Singh said he has got the understanding of social and political issues. Besides being a member of the Gandhi family, he has the qualities of head and heart to strike rapport with people, he said.
Singh, who is in charge of party affairs in Uttar Pradesh, dismissed suggestions that BSP supremo Mayawati, SP chief Mulayam Singh Yadav or the BJP leaders could be termed his rivals.
"He competes with himself, not with others", Singh said when asked as to who is Rahul''s main competetor in politics.
Dismissing opposition charges that Rahul indulges more in theatrics than in real action, he said, "Rahul works with the courage of conviction. He works with commitment and confidence".
Singh, who had a meeting today with Prime Minister Manmohan Singh, declined to divulge what transpired between them saying it was a "routine" affair.