English Defence League (EDL) leader Stephen Lennon, 30, pleaded guilty to possession of a false identity document with improper intention, contrary to the Identity Documents Act 2010, at Southwark Crown Court.
Lennon used a passport in the name of Andrew McMaster to board a Virgin Atlantic Flight from Heathrow to New York, but was caught out after his fingerprints were taken by customs officials.
He left the airport and entered the US illegally but left the country the following day, using his own passport to return to the UK.
More top news
Legal action has been threatened against the Parole Board if it does not disclose the reasons behind its decision to release John Worboys.
The PHE will review the evidence and also make recommendations on how to address the issue, according to health officials.
The Commons Public Accounts Committee (PAC) said at least £9 million has been squandered on a project that failed to deliver.