"I am really not well and I have violated certain fundamental values. I feel guilty and that's why we made this decision, and I am suspending party membership for a year," Vareikis told BNS.
Asked whether he considered stepping down as an MP following the weekend incident when the police were called in to deal with a case of domestic violence, he said no.
A pre-trial investigation into domestic violence at Vareikis' home is underway.
Police say Vareikis hit his wife in the face twice on Saturday night.