CARMARTHEN East and Dinefwr MP Jonathan Edwards has accepted a police caution for assault after officers were called to his home last month.
Mr Edwards, 44, was arrested on May 20 on suspicion of assault.
A personal statement released on behalf of Mr Edwards said: "I am deeply sorry. It is by far the biggest regret of my life. I complied fully with the police and acted with the best interests of my wife and children as my primary motive throughout.
"My priority now is to work with my wife to ensure as stable a future as possible for our family."
His wife, Emma, has also released a statement, saying she has "accepted her husband's apology".
Mr Edwards has referred himself to Plaid Cymru's internal disciplinary committee and remains suspended from the party, which means he is effectively sitting as an independent MP.
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