The leader of the English Defence League has been jailed for 10 months for using someone else's passport to travel to the USA.
Stephen Lennon, 30, from Luton, admitted possession of a false identity document with improper intention.
Lennon used a passport in the name of Andrew McMaster to board a Virgin Atlantic flight from Heathrow to New York, Southwark Crown Court was told.
He entered the US illegally then used his own passport to return to the UK.
Lennon had previously been refused entry to the US and used a friend's passport to travel to the country in September.
He used a self check-in kiosk to board the flight at Heathrow and was allowed through when the document was checked in the bag-drop area.
But when Lennon arrived at New York's JFK Airport, customs officials took his fingerprints and realised he was not travelling on his own passport.
Lennon was asked to attend a second interview but managed to leave the airport, entering the US illegally.
He stayed one night and travelled back to the UK the following day using his own legitimate passport, which bears the name of Paul Harris.
Judge Alistair McCreath told him: "I am going to sentence you under the name of Stephen Lennon although I suspect that is not actually your true name, in the sense that it is not the name that appears on your passport.
"What I have to deal with you for is clear enough. You knew perfectly well that you were not welcome in the United States.
"You knew that because you tried before and you had not got in, and you knew the reason for that - because, rightly or wrongly, the US authorities do not welcome people in their country who have convictions of the kind that you have.
"With that full knowledge, you equipped yourself with a passport. I am told that it was given you by way of a loan from your friend Andrew McMaster, to which you bore, I am told, some resemblance."
The judge added: "What you did went absolutely to the heart of the immigration controls that the United States are entitled to have.
"It's not in any sense trivial."
In mitigation, Lennon's barrister Giles Cockings told the court the passport was not stolen and his client had only used it for a day.
Lennon was jailed for assault in 2005 and also has convictions for drugs offences and public order offences, the court heard.