Security for Britain's royal family will be investigated by an independent commission after revelations yesterday that an undercover reporter posed as a Buckingham Palace footman, the Home Secretary, Mr David Blunkett, said.
Embarrassed royal officials also launched an inquiry after "insufficient" checks allowed the security breach during the build-up to President Bush's state visit.
Mr Blunkett, who was moved to make an emergency statement to MPs in the House of Commons, insisted security vetting procedures on the reporter were carried out "robustly and correctly".
But he added: "I am concerned that the system as a whole needs to be reviewed urgently. The Prime Minister, with the support of the Royal Household, is therefore asking the Security Commission, which is an independent body responsible for overseeing breaches of security, to conduct a thorough review.
"I would expect this to cover all aspects of the process of checking those who form part of the royal household."
While the Home Office's security and criminal records checks had been successful, employment checks "proved insufficient in this case", Mr Blunkett said.
Daily Mirror reporter Ryan Parry used a fake reference to get the job, which he held for two months as police and royal staff prepared for the arrival of the US president.
He was due to serve breakfast to the President's top aides yesterday morning, the newspaper said.
It ran 15 pages yesterday, including pictures of Mr Parry dressed in red livery and shots from inside the palace, including the president's bedroom, the queen's breakfast table and the Duke of York's room, complete with soft toys.
The reporter 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."
Mr Blunkett said details of the Security Commission's review were still being agreed but he expected an interim report by the end of the year. In August, Mr Parry responded to a job advertisement on a recruitment page of the Buckingham Palace official website. On his CV, he excluded details of his journalistic career and included one fake reference and a real one, the newspaper claimed.
Mr Parry claimed no rigorous security checks were done on his background.
Despite this, he claimed he was given a full, all-areas security pass on his first day and had direct access to the queen's food, which he said he could have easily poisoned.
He added that just days ago, in the midst of the security ahead of the president"s visit, he was able to walk through rooms he and his wife would use, taking photographs of the bedroom.
Mr Parry left the palace on Tuesday night after the arrival of President Bush and his wife, the Mirror reported.