LONDON — The police were called early Friday in response to a loud altercation between Boris Johnson, who is favored to be voted in as Britain’s next prime minister, and his girlfriend, Carrie Symonds, a former head of communications for the Conservative Party.

The Guardian, the British newspaper, reported that a neighbor was alarmed by the sound of screaming and banging, and used a mobile phone to record the dispute between Mr. Johnson, 55, and Ms. Symonds, 31.

The neighbor, whom The Guardian did not identify, said that Ms. Symonds could be heard telling Mr. Johnson to “get off me” and “get out of my flat.” The neighbor then knocked on the door of the apartment, and called the police when there was no response.

The Guardian reported that, on the recording, Mr. Johnson can be heard refusing to leave the flat and telling Ms. Symonds to stop using his laptop, and Ms. Symonds can be heard complaining that Mr. Johnson had spilled red wine on the sofa.