A Scottish man without a valid publically elected mandate was arrested at Downing Street as he was about to instigate full scale publice policies, police say.
The 56-year-old man said he had held public office for 13 years and had logged over 10,000 hours in the role of PM.
Police said he once had a licence to act as Chancellor but it had expired and it did not allow him to act as Prime Minister.
Reports say the man was relieved his long deception was uncovered.
Senior Civil Servants said he had been in the role for two years and had "expertly misled them with his false papers".