If PAS is truly Islamic they should show proof of claims that the BN government has denied the state its rightful oil royalties, said BN deputy president Muhyiddin Yassin.

The deputy prime minister said BN expects PAS to attack them on the issue in the Pengakalan Kubor by-election campaign, and are ready to respond.

"We know it will be made the central (election) issue. We are not afraid," he said after nominations in the Kelantan constituency today.

"We the BN government have never cheated the people.

"If PAS is truly an Islamic party, they should (raise the matter) the Islamic way.

"So I want to challenge PAS to give explanations and proof that the federal government owes Kelantan (oil royalties)," said Muhyiddin.

He was speaking at a press conference after nominations in Tumpat constituency.

Poor oil producing state

Under former prime minister Dr Mahathir Mohamed’s administration, the government ceased paying royalties from Kelantan's oil production after PAS took control of the state government in 1990.

After years of protests by PAS, Prime Minister Najib Abdul Razak in 2012, a year before the 13th general election, invited the party to join a committee to discuss oil royalty payments to Kelantan.

At the time, Kelantan Umno chief Mustapa Mohamed also announced that the matter can be resolved before the general election last May 5.

The Kelantan government, however, has expressed disappointment that its representatives have yet to receive any news about the committee meeting.

It is now seeking to claim its oil royalties through an interlocutory injunction to stop Petronas from paying the royalty directly to the federal government or its agents.

In the application, the Kelantan government said the oil revenue should be given to the state instead.

Despite its oil production, the state is the second poorest in Malaysia, and remains under PAS administration.