The son of the shadow home secretary Diane Abbott has admitted spitting at a police officer and biting his colleague outside the Foreign Office after being refused entry.
James Abbott-Thompson, 28, was working as a diplomat for the government department after graduating from Cambridge University.
He went to the building on November 29, asking to see a member of staff he knew, and became angry when told they were not there.
Police were called to the Foreign and Commonwealth Offices in King Charles Street, Westminster, where Mr Abbott-Thompson attacked them when they asked him to leave. He also admitted wrecking a glass plaque and assaulting a third man in the incident.
Misba Majid, prosecuting, had earlier said: "It is an assault on two police officers after an incident taking place at the Commonwealth Offices. The Commonwealth Offices called the police.
"He was there because he wanted to speak to a member of staff who was not present. When the police arrived, they politely asked him to leave. He refused to do so.
"He has gone on to whisper and the officer could not hear him, so has come closer to him and he has gone on to spit in their face. He has spat in the face of the officer PC Stefan Aqua. He has then managed to break one arm free and punch PC Aqua in the face.
"He then tried to punch PC May, and then grabbed PC May's left thumb and bit him.'
Ms Abbott, the MP for Hackney North and Stoke Newington, was not in court to support her son, who appeared via video link and was wearing an orange vest with a grey jumper and glasses.
Mr Abbott-Thompson spoke only to confirm his name and date of birth and admit the charges before thanking the judge at Westminster Magistrates' Court.
At the age of 27, he was working alongside the British Ambassador in Italy advising the British Consul and the British community in Italy about their rights after leaving the European Union.
After two-and-a-half years in London, he was stationed at the British Embassy in Rome and appointed as First Secretary for Exiting the EU.
Abbott-Thompson, of Tottenham, north London, admitted threatening behaviour, criminal damage, assault by beating and two counts of assaulting a police officer.
He will return for sentencing on April 8.