Najib Abdul Razak has called out Finance Minister Lim Guan Eng for claiming that the new sales and service tax (SST) is not solely responsible for the rising prices of goods, despite previously blaming the now-defunct goods and services tax (GST) for the same.

The former prime minister was responding to Lim's statement on Thursday that the increasing prices were not entirely due to the SST, reintroduced by the new Pakatan Harapan government this month after repealing the GST enforced during the Najib administration.

Lim had stated that other factors, such as supply and demand, imported goods, depreciation of the ringgit, festive seasons, smuggling activities and profiteering by businesses contributed to the higher prices.

"Finally, Lim admits that the price of goods have also increased after the SST was enforced, even though his assistant (special officer to the finance minister) Tony Pua once insisted that the prices of goods would decrease with the SST," Najib said in a Facebook posting.

According to the Parliament Hansard, however, Pua had stated that prices of goods would be cheaper under the SST in comparison to the GST.

"Before this, he (Lim) had repeatedly said GST was the cause of increased prices of goods. He even sang a song about GST with some children.

"Now he is saying higher prices are not due to SST but many other factors. Perhaps there will be a song on SST after this?" he quipped.

Najib was referring to an anti-GST song heard at a launching ceremony for free tuition classes at the Mutiara Idaman 2 flats in March, during which Lim led the children present in a singalong.

A media report quoted Lim saying at the time that he had obtained the music video from the internet and decided to share it because he found it interesting and easy to sing.

The opening Bahasa Malaysia lyrics of the song go: “ABCD-GST, prices (of goods) are rising. Salaries have yet to increase, so we have to eat Maggi (instant) noodles.”

The song-and-dance act saw Lim being investigated by police under Section 223(1)(a) of the Communications and Multimedia Act 1998.