PAS said it will reject cooperation with Umno if the party partakes in political re-alignments hinted in the audio clip allegedly of Umno president Ahmad Zahid Hamidi and PKR president Anwar Ibrahim.
PAS president Abdul Hadi Awang also that his party will only negotiate seats with Umno once the latter settles their "problems".
This comes as PAS continues to push back against Umno's urgings for the Islamist party to ditch Bersatu.
Speaking to reporters in Marang, Terengganu, Hadi said he did not know whether the recording - purportedly of Anwar congratulating Zahid's handling of the Umno general assembly - was real.
However, he said the people can judge for themselves its authenticity, and said the recording was a sign of new political alignments.
"The new alignment has been announced, this is one of the signs," Hadi said.
The new alignment is a phrase used to depict possible cooperation between Umno and PKR or Pakatan Harapan.
Zahid and Anwar both claimed the recording is fake. Zahid has also said that Umno will not cooperate with PKR in the next election.
Asked whether PAS would continue to work with Umno if such a re-alignment occurred, Hadi replied in the negative.
"We will remain with Perikatan Nasional. We reject the new alignment... we won't accept it," he said.
He then reiterated that PAS wants to retain the Muafakat Nasional pact with Umno, but this must also include Bersatu.
"Muafakat is not just PAS and Umno, but also Bersatu. The issue of Umno not adhering to this is their problem," Hadi said.
Umno and PAS had invited Bersatu to join Muafakat in August last year, which the latter agreed to.
However, there was no follow-up on the matter.
PAS deputy president Tuan Ibrahim Tuan Man claimed last week that there was no reply on Bersatu accepting the invitation to join Muafakat because Umno was disappointed that the pact could not be registered formally.
This narrative is being used by both PAS and Bersatu to pressure Umno against going solo in the next election.
Meanwhile, on seat negotiations, Hadi said PAS will not engage with Umno for now.
"This is incumbent on Umno resolving their problems first. We had a (seat negotiations) committee before, but Umno changed midway.
"Up to now, because Umno is problematic, we (negotiate) with Bersatu first," he said.
He said PAS has appointed leaders for seat talks with Bersatu, and that he would leave the matter to them.