SM Krishna, who is now in the BJP, alleged Rahul Gandhi issued diktats without holding any post. (FILE)

Former External Affairs Minister SM Krishna on Saturday alleged that he had to quit the Manmohan Singh-led government and the Congress party due to constant interference by Rahul Gandhi.

The former Congressman, who is now in the BJP, alleged Mr Gandhi issued diktats without holding any post.

"I was external affairs minister for 3.5 years and Manmohan Singh had no say over that portfolio. Rahul Gandhi was then a nobody, not even a general secretary. He issued diktat that those who turned 80 can't be a minister. When I heard that, I submitted my resignation and came to Bangalore," Mr Krishna said at an event in Karnataka's Maddur.

"This is what they call extra-constitutional authority. He (Rahul Gandhi) was not answerable to anyone-- neither Parliament nor governance," the BJP leader said about Mr Gandhi who had torn up an ordinance at a press conference back in 2013.

Alleging further that the environment was not conducive for governance during UPA rule, Krishna blamed compulsions of coalition politics for alleged scams during Manmohan Singh-led government.

"Manmohan Singh was the Prime Minister but had no control over his Cabinet colleagues. It was during that period that scams broke out," Mr Krishna alleged.

Mr Krishna, who hails from Karnataka, was the state Chief Minister from 1999 to 2004. He joined the BJP in 2017 after having spent decades in the Congress party.