Police were called to help disperse a large crowd who had gate-crashed a private party held at a Conservative MP's house.
Simon Kirby, the Tory member for Brighton Kemptown in East Sussex, said he was "personally upset" by the intrusion and that his family had "learnt lessons" from it.
The crowd reportedly of up to 100 people turned up uninvited while a small gathering of friends was being hosted at his home on August 12, although details have only just emerged.
It was unclear how the strangers heard about the party but there were suggestions that rumours may have spread through social networking websites.
Mr Kirby, who holds a 1,328 majority, said his 19-year-old daughter, who organised the party, called in police after she tried to get the invaders to leave.
Mr Kirby, who was unavailable for comment, said in a statement to the Brighton Argus: "The party was a one-off private event involving my family, and I have now dealt with the issue. I am personally upset that what was meant to be a small gathering of friends was gate-crashed by others.
"It was ... my daughter who very sensibly contacted the police when it was clear the event had been gate-crashed and she was not able to move the unknown attendees on.
"There was no loud music, and I think it is safe to say, like most families, we have learnt lessons from this. I want to thank the police for their prompt action."
Married to Elizabeth, Mr Kirby has six children and jointly-owned leisure business C-Side with partner Martin Webb, and is a life-long Brighton and Hove Albion FC fan.
There were no arrests and no-one was injured, a Sussex Police spokeswoman said.