Shafie Apdal has come under fire from Najib Abdul Razak, who leaked appeal letters concerning government projects when the Warisan president was in the former premier's cabinet.

Najib accused Shafie, who was the rural and regional development minister at the time, of being the most frequent in rejecting the open tender process.

He also claimed that Shafie appealed to him on numerous occasions to choose a selective tender as opposed to an open process.

Asked for his response on this, the Sabah chief minister said he fell in Najib's crosshairs after being named as a possible prime minister candidate for Pakatan Harapan and its allies.

"I suppose he (Najib) was concerned when Dr Mahathir (Mohamad) mentioned my name as a candidate for PM-9. It (the attack) never happened (before).

"Only when this issue cropped up, I became (his) target," he told a media interview in Kuala Lumpur yesterday.

Not willing to discuss the issue initially, the Sabah politician claimed that he kept similar letters which Najib had signed.

However, Shafie said he does not want to go down the same road as Najib and accused the former premier of having his fair share of such practices too.

"There were times when we had open tender, and they (those who failed in their bid) said they wanted to make an appeal. And they went to see Najib.

"After they saw Najib, they conveyed a message to me that Najib had agreed. They only need an appeal letter," he claimed.

Stressing that there was nothing illegal with writing letters of appeal in the government, Shafie disagreed with singling him out over the matter.

He claimed that Najib had also signed letters approving appeals for government contracts before.

"They shouldn't be saying now that I made this and that appeal. I have copies of those letters too.

"I have copies of letters where he (Najib) signed and approved, and I know.

"But I don't want to (reveal the letters as Najib did). It is okay," Shafie added.

On Saturday, Najib posted on his Facebook page photos of two letters bearing Shafie's signature, which the latter addressed to Najib, appealing to the then PM to reconsider two project tenders.

The letters, both dated in 2013, concerned road-building projects in Johor and Sabah.