Umno has no reason to open its membership to non-Malays, Communications and Multimedia Minister Salleh Said Keruak said.
Salleh said this is because the BN model is meant to allow each party to retain its ethnic identity.
Umno, he said, "has never claimed to be a multi-racial party", like what the DAP claims itself to be.
"In fact, neither has MCA or MIC made this claim as well. All three parties admit to being ethnic-based.
"And that was why the Alliance Party was created in 1952 - so that Umno, MCA and MIC can retain their ethnic base and yet come together under a multi-racial coalition," Salleh said in his blog.
He was responding to DAP's Gelang Patah MP Lim Kit Siang, who challenged Umno to open its membership to non-Malays.
This comes as DAP continues to defend its multi-cultural identity.
The DAP has MPs and members of various races, but is predominantly made up of ethnic Chinese members.
This has caused it to be painted as a "Chinese party", with critics claiming it is anti-Malay as well.
DAP tries to challenge this by celebrating its Malay recruits, and is mulling fielding Malay candidates in majority Malay areas in the coming general election.
However, Lim stressed that this is not new and that the DAP has contested in several Umno strongholds since its early days in the 1960s.