He said nothing in the draft unity government agreement, drawn up before its formation, forbids its components’ leaders from joining other parties.

“This will need to be discussed among unity government components because this is a grey area.

“(However, accepting Tengku Zafrul) should be avoided because it opens the door to uncertainty.

“Where do you draw the line when Umno leaders criticise (the move)?” he told reporters in Ampang today.

When asked if PKR should also be open to its leaders moving to other parties, should it accept Tengku Zafrul into its ranks, Rafizi said the party’s top leaders should come forward to explain the party’s stance.

He said the criticisms levelled by Umno leaders against Tengku Zafrul were valid and deserve the attention of the unity government’s leaders.

Earlier, Umno secretary-general Asyraf Wajdi Dusuki said it is “very inappropriate for any party in the unity government to arbitrarily accept members from other allied parties”.

“This is to prevent causing disharmony among the parties in the unity government. This could lead to continuous prejudice and suspicion among grassroots members about the level of loyalty, sincerity and honesty that we have,” he said.

Umno’s legal bureau has also been asked to look into the implications of Tengku Zafrul’s exit from the party in terms of the party hopping law and on his status as senator.

The party’s information chief, Azalina Othman Said, said while Umno respects a person’s right to make political choices, Cabinet appointments are based on the party represented instead of one’s individual capacity.

She said while the prime minister chairs the national unity council, Cabinet ministers are appointed as the party’s representatives.

On Friday, Tengku Zafrul said he had submitted his resignation as an Umno member as well as from all party posts.

He said he had informed PKR president Anwar Ibrahim and secretary-general Fuziah Salleh of his intention to join PKR.