Deputy Prime Minister General Prawit Wongsuwan on Friday got involved in an online argument with former Prime Minister Yingluck Shinawatra over state spending, comparing the rice mortgage scheme to the submarine purchase.

Activist Srisuwan Janya plans to petition with the Office of Auditor General on Thursday to investigate whether the purchase of a Bt13.5-billion Chinese-made submarine violated the Constitution and relevant laws, he said on Wednesday.