The Queen has won a High Court order blocking a newspaper from revealing more details about the Royal Household.
Mr Parry broke cover on the eve of President Bush's visit
The Daily Mirror's Ryan Parry got a job in September as a footman at Buckingham Palace using a false reference.
His identity was revealed by the paper the same day US President George Bush arrived in the UK for a state visit.
The Royal Household, which accuses Mr Parry of breaching a confidentiality agreement, was granted an injunction until 1630 GMT on Monday.
It had earlier said it would sue both Mr Parry and the paper.
The revelations in the Mirror put pressure on the government, Buckingham Palace and Scotland Yard, which has spent £5m and put more than 5,000 police on the capital's streets for Mr Bush's visit.
A Buckingham Palace spokeswoman said: "We sought this injunction in order to
protect personal privacy and we are satisfied with the progress made this
A White House spokesman told the BBC on Wednesday that despite the security breach at the palace, "the White House still has confidence in British security".
The Daily Mirror story included pictures by photographer Phil Harris from inside the palace of the bedroom used by Mr Bush and his wife, The Belgian Suite.
There were also pictures of the Queen's breakfast table and the Duke of York's room.
Mr Parry wrote: "Had I been a terrorist intent on assassinating the Queen or
American president George Bush, I could have done so with absolute ease.
"Indeed, this morning I would have been serving breakfast to key members of his government, including National Security Adviser Condoleezza Rice and US
Secretary of State Colin Powell.
"Such is the shocking incompetence at the heart of the biggest security
operation ever in Britain."
In August, Mr Parry responded to a job advertisement on a recruitment page of the Buckingham Palace official website.
On his CV, he left out any mention of his journalistic career and included one
fake reference and a real one, the newspaper claimed.
Mirror editor Piers Morgan said the paper used "very basic subterfuge and got incredible access".
"To our surprise and then mounting horror we discovered that our man with no training, no experience at all, no real vetting was in very close proximity to the most important people in our country," Mr Morgan told BBC Radio 4's Today programme.
He described the reference checking as "scandalous" and "shoddy".
Mr Morgan alleged that someone from the palace rang Mr Parry's local pub where he had given a name as a character reference.
"That person had left and they shouted down the bar: 'Does anyone know Ryan Parry?' To which some man in the corner drinking, said: 'Oh, I know him, he's a good guy'."
Mr Morgan said they had decided to pull Mr Parry out of the palace once the president arrived as "we did not want to genuinely compromise any ongoing security issues that might arise while [the president] is here."
Mr Parry had previously gone undercover at Wimbledon tennis championships to reveal security flaws.
Mr Blunkett said he was "obviously concerned" about the alleged security flaw.
However, he said he was "satisfied that the security and criminal records checks had been done robustly and correctly and that there was no risk from the reporter".
He said that "there were wider issues to see if lessons should be learned about how checks are undertaken".
The alleged security flaw will compound the embarrassment caused by comedian Aaron Barschak, who gatecrashed Prince William's 21st birthday party in June.
An inquiry following that incident highlighted a number of police errors in guarding Windsor Castle.