A 32-year-old man was last night charged with possessing "a bladed article" and assaulting a police officer following a Downing Street security breach.
Byung Jin Lee, of no fixed address, appears before City of Westminster Magistrates' Court at 10am this morning, Scotland Yard said.
Security at the Prime Minister's residence was last night under review after the man was alleged to have climbed into a secure area armed with a knife on Sunday night.
The man was said to have scaled a 6ft high set of iron railings behind the address at 10.35pm.
Tony Blair was believed to have been at home at the time.
Police officers were said to have overpowered and arrested the man.
Detectives were satisfied there was no terrorist link to the incident and that there was never any threat to Mr Blair's safety.
The alert began at 10.35pm on Sunday when the 32-year-old intruder scaled the railings which divide Horseguards Road from Horseguards Parade at a point just 100 yards away from the last house on Downing Street.
Police were alerted as soon as he dropped to the ground into what is known as the "Lshaped road" to the rear of the Prime Minister's residence.
The moment he landed, he was challenged by an officer from the Metropolitan Police's Diplomatic Protection Group.
The intruder tried to lunge at the officer, but it is not thought that he wielded his knife during the brief struggle that followed.
He was eventually pinned to the ground, handcuffed and arrested as other police officers arrived.
A large kitchen knife was found in his possession.
It was quickly removed and will now be forensically examined.
The intruder was arrested and taken to a central London police station where he was examined by a doctor to see if he was fit to be interviewed.
It is understood that the man's mental health will be assessed.
He was held on suspicion of affray and assaulting a police officer.
Police sources stressed that the man came from an area where the public is entitled to be and that as soon as he landed in the secure area he was challenged.
He only managed to gain access to an outer secure area and was only around two metres inside when he was confronted by the police officer.
To have made it over the next wall and inside, he would have needed to breach another layer of security, which sources said was highly improbable.
The Prime Minister's residence is bordered to the rear on one side by a high brick wall which encloses the famous rose garden.
The actual part of the street from where the front doors of Numbers 10 and 11 can be reached is only accessible via security gates, which sit at either end.
Scotland Yard's Counter Terrorism Command was informed of the incident but it is not handling the investigation. Instead, Westminster Police are investigating.
A spokesman for Scotland Yard said: "At this stage we believe he scaled a fence off Horseguards Parade. As he got to the other side he was challenged by an officer and arrested following a short struggle.
"We are satisfied that at no time was the Prime Minister at risk."
Despite this, security at Downing Street will be reviewed.
"The incident will prompt a review of security, as is routine," the spokesman added.
This will examine how the man was able to scale the railings and whether there are any lessons to be learnt.
Other high profile security breaches in recent years include pro-hunting demonstrators entering the House of Commons chamber and the gatecrasher at Prince William's 21st birthday party at Windsor Castle.