Why Tushar Mehta was given 4th extension as Solicitor General?

Centre has given Solicitor General Tushar Mehta a fourth extension for three years from July 1. His extension may be linked to his role in representing the Centre in many landmark cases involving national security, electoral reform, and Centre-state disputes. Further, he has been a regular counsel before Constitution Benches of the Supreme Court in cases with far-reaching policy implications.