Prime Minister Najib Abdul Razak was observing Finance Minister II Johari Abdul Ghani wrapping up the ministry's part in the Budget 2017 policy stage debate on Monday night.

Najib, who was in Parliament that night, watched Johari in action from the Speaker's Chambers, revealed Speaker Pandikar Amin Mulia.

"He sat (in the room) and he observed the debate through the closed circuit cameras. He wanted to observe the second finance minister," Pandikar said when asked what Najib was doing in his chambers that night.

Asked if Najib was pleased with Johari's delivery, Pandikar replied: "He smiled, he didn't say anything."

Najib had walked into the Parliament building about halfway through Johari's winding up speech on Monday night.

He left about an hour later, as Johari ended his speech, following a heated exchange in the House, with Puchong MP Gobind Singh Deo daring Najib to come out an answer allegations about the 1MDB scandal.

Johari was the last minister to wind up, and a bloc vote on Budget 2017 was called just minutes after Najib left.

The budget passed the policy stage with 117 votes in favour, and 70 votes against. Eleven lawmakers, all from PAS, abstained from the vote.

The prime minister had previously chastised the opposition for walking out of the House while he was tabling Budget 2017.