He also brushed aside demands for his own resignation and declined to respond to allegations that he used Kumar as a shied to "safeguard" himself.
"There is no question of the Law Minister resigning. The matter is now in the court and it is sub-judice. It is not proper for me to do anything. But there is no question of the Law Minister resigning," he told reporters in Rashtrapati Bhawan when asked whether he would seek Kumar's resignation.
On BJP's charge that he was using the Law Minister as a shield to "safeguard" himself in the coalgate probe, Singh said, "I would not like to comment on this subject. It is a matter which is now before the court."
He dismissed the opposition demand for his resignation on the coal blocks allocation scam, saying this was not the first time they were making such a demand.
He also appealed the opposition to let the Parliament function and discuss all the issues there.
"By not allowing Parliament to function, we are making mockery of our system of democracy. The whole world is laughing at us. Whatever the issues, these can be debated, discussed and decisions arrived at through proper dialogue at Parliament," he said.