Government today replaced Solicitor General Gopal Subramanium with Attorney General G E Vahanvati to represent Prime Minister in the Supreme Court in the 2G spectrum case in the wake of strong observations from the bench.Mr.Vahanvati said in New Delhi that the government has asked him to represent the Prime Minister in the case. The Supreme Court had on Thursday asked the Prime Minister to file by Saturday an affidavit on alleged inaction in responding to a plea seeking sanction to prosecute ex-Telecom Minister A Raja in the spectrum case, calling the matter extremely serious.