The Chinese form the core constituency of the Democratic Action Party (DAP), which is a part of the opposition alliance. In the past, the DAP has opposed hudud laws, which prescribe harsh penalties like cutting off limbs for theft.
"I'm confident that DAP will accept hudud law because of its willingness to contest under the PAS symbol. However, this can only be done after Pakatan is given the mandate to rule the country," said Dr Haron Din.
"Pakatan must take over the Federal Government. Only then can we amend the (Federal) Constitution to implement hudud law," he said after visiting single mothers at Guar Sanji on Tuesday.
Although DAP had rejected the implementation of hudud law a few years ago, it is now no longer the case, he added.
Dr Haron, who is Arau parliamentary seat candidate, said Pakatan parties must "give and take" in order to work together.
For example, he said, DAP should agree with PAS' decision not to allow the use of the term "Allah" by non-Muslims.
Meanwhile at another function in Alor Setar, PAS ulama council chief Harun Taib said all Muslim women should wear tudung (headscarves), not just students and newscasters.
Hailing former Umno vice-president Tan Sri Muhammad Muhammad Taib's resolve to promote the Islamic way of life, the PAS leader stressed that the campaign to get Muslim women to wear tudung should not be targeted at specific groups.
"It should be targeted at all Muslim women," he said on Tuesday but added that Muslim women could not be forced to wear tudung.
Mr Harun was responding to Mr Muhammad's remarks on Monday after joining PAS when he said there were Muslim women newsreaders and schoolchildren who did not wear tudung.
"They say Islam, but look at the newsreaders not wearing headscarves. They say Islam, but there are schoolchildren who wear skirts," he was quoted as saying.
Mr Muhammad, who is the former Selangor mentri besar, also said that while the nation and Selangor had undergone tremendous development, he felt that it was a "development with-out soul" which had led to moral decline among children of affluent families in the cities.