Police need to look beyond the available intelligence and take a broader view of potential threats, a report into the attack on a car carrying the Prince of Wales and the Duchess of Cornwall has found.
Home Secretary Theresa May said important lessons have been learned from the mob attack on the royal car in central London on December 9.
"The most significant area of learning from the incident is the need to look beyond the available intelligence to take a broader view of threats that can reasonably be anticipated in the circumstances, and to adapt plans accordingly," Mrs May said.
Metropolitan Police Commissioner Sir Paul Stephenson ordered an internal review into the incident, which was presented to Mrs May last month.
In a written statement to MPs on Monday, she said the details of its findings could not be released for security reasons but "the overarching recommendations relate to operational planning and the co-ordination of personal protection and public order policing".
"While important lessons have been learned from this shocking incident, the findings and recommendations must be seen in the context of the provision of protection for the Royal Family that has an enviable record over many years," she said.
"Such protection always has to take into account the Royal Family's desire to be seen by, and to be close to, the public."
Earlier this month, police released footage showing the moment a mob descended on the royal car. Senior officers hope the images will help them identify those responsible for the attack in Regent Street in London's West End.
A crowd of thugs who split from student tuition fee protests outside the Houses of Parliament descended on the distinctive Rolls-Royce Phantom VI.
The council CCTV film showed the royal convoy, led by several motorcycle police outriders, slowing down as it was impeded by people in the road. Several people surrounded the royal car, kicking and hitting it and Camilla was poked through an open window with a stick.