Dr Mahathir Mohamad said today Putrajaya should consider "blowing up" the North-South Expressway (Plus), which was one of his major projects when he was in power.

This was his sarcastic response to reports that attempts were being made to destroy his legacy, with TV3 launching a campaign against national automaker Proton, which was his brainchild.

"Some people said I have done many bad things, such as the North-South Expressway. We should actually blow it up," he told a press conference in Kuala Lumpur today, prompting laughter among journalists.

"The Kuala Lumpur International Airport, the Petronas Twin Towers, all these things are very bad you know," he added with a wry smile.

Earlier today, former information minister Zainuddin Maidin, an ally of Mahathir, claimed TV3 had been instructed to attack Proton.

He said this was a bid to smear anything associated with Mahathir, who has relentlessly attacked Prime Minister Najib Abdul Razak on 1MDB which had accumulated RM41.8 billion in debt.

On a separate matter, Mahathir said the government's plan to revise the toll for at least 16 highways upwards may be an attempt to get funds to pay off its massive loans.

"May be they need to pay for the loans they took out," he said.

He added this was on top of already using RM6 billion in funds the government collected under the Goods and Services Tax.

Since the last general election, the government had held back any toll hike for road users but must still pay the toll concessionaires directly under the agreement with them.