Palaniswami said Stalin had failed in his earlier bids to "topple" the government and therefore, was targeting him on this matter.
"He tried all tricks (against the government). He tried to topple the government. (During last year's confidence vote), his party MLAs even occupied the Speaker's chair," the chief minister said.
Responding to reporters' queries on criticism by Stalin in the wake of the court direction for a CBI probe into the case, he alleged the Leader of Opposition was on the "verge of frustration" and was resorting to "slander" against him.
Palaniswami charged Stalin with trying to break the AIADMK earlier and accused him of "instigating" some people within the ruling party. However, he did not name anyone.
"They (DMK) thought that this government will fall after the death of Amma (lJ Jayalalithaa). They said the party will split, but nothing happened.
"Things that he (Stalin) expected are not happening. So, he is now sticking to this issue," the chief minister said.
Palaniswami, who also holds the highways portfolio, denied any irregularity in the award of contracts and rejected the DMK's charges that they were given to his relatives.
Claiming that proper procedures under the E-tender system were being followed and there was no scope for any irregularity, he said the person who won the contracts had also bagged projects during the DMK rule.
He claimed the government has come across instances of "excess" payments made to certain contractors during the DMK's tenure.
Asked if the government would file a case in this regard, Palaniswami said he could respond only after consulting legal experts.
On October 12, the Madras High Court had ordered a CBI probe into allegations of corruption in the award of government road contracts, giving ammunition to opposition parties to attack the chief minister.
Palaniswami declined to comment on the Supreme Court verdict allowing entry of women of all age groups into the Sabarimala shrine.