THOUSANDS of troops, including military police from Colchester, are on standby to patrol London's streets if they are needed.

The Red Caps are among 5,000 troops which could be called on if the Metropolitan Police is not able to withhold a high-level of security in the capital.

The move comes after Wednesday's terror attack near to Parliament and Army chiefs have attended meetings to make sure troops are ready to deploy.

Armed soldiers would be used to release police resources from duties such as guarding public buildings.

They would be escorted by unarmed police officers.

A Ministry of Defence spokesman said: "In close consultation with other Government departments, the MOD frequently plans for a range of contingencies which might be required in times of crises.

"Defence assistance will most likely be requested when the need to act is clear and civilian police require additional capacity to deal with the breadth of an incident.

"Although Defence does not have standing conventional forces for this requirement, it does have the agility and capability to provide support at short notice."