Umno has filed a lawsuit against the MPs who defected from the party.
This was revealed by Umno president Ahmad Zahid Hamidi during a dialogue with party members in Kuala Lumpur tonight.
"They (defecting MPs) need to know that they did not win on their own accord, they represented Umno under the banner of BN.
"They won on the backs of hardworking Umno members and the party machinery, and they should be thankful for their victory, not switching parties for their personal interest.
"Taking this into account, I would like to announce that the Umno headquarters on Nov 14 filed a writ of summons to demand compensation (from these MPs)," he said.
According to Zahid, the suit will demand a "large sum" from the defecting lawmakers.
"We will sue all of them not only based on the Election Offences Act 1954, but through all legal means.
"What they owe to Umno and its machinery must be repaid," he said.
Despite losing power in the May 9 general election, Umno managed to remain the largest party in the Dewan Rakyat with 54 MPs.
However, it is now the third largest behind PKR and DAP, after an exodus of its leaders left it with just 38 MPs.
At least three have joined Bersatu and one Parti Warisan Sabah. The remaining lawmakers remain independents.