Two thousand RUC officers and British soldiers are on standby to be deployed into Portadown to uphold the Parades Commission ruling on the Drumcree march, according to the senior RUC officer in charge of the operation.
Assistant Chief Const Stephen White said five British army battalions were at his disposal, including the Parachute Regiment.
However, he stressed yesterday that deployment of troops on the ground would be proportionate to any situation facing the security forces.
At the height of any standoff 1,000 police officers and 1,000 soldiers may be deployed. "There are lots in reserve, but we will deal with the situation at hand and not up the ante," Mr White said.
A single RUC Land-Rover was stationed near the bridge at a quiet Drumcree Parish Church yesterday.
The bridge is the flashpoint between loyalist protesters and the security forces as their access to the nationalist Garvaghy Road is blocked.
Mr White said he expected the main barrier at the bridge and other fortifications would be erected before tonight. "We are preparing for the worst but are hoping for the best. It will only take one spark to ignite or inflame the situation," he said. Any paramilitary display at Drumcree Hill was unwelcome.
British army convoys patrolled the roads around the town yesterday, while additional army vehicles could be seen making the journey from the barracks at Lisburn. "We started this operation 10 days ago, and it is now in the first phase which involves extra patrols looking at interface areas and protecting both communities," Mr White said.
The second phase of the operation is the protection of the outward route for the Portadown LOL No 1 parade, which leaves Carlton Street at 9.30 a.m. tomorrow.
The third phase of the security operation is the upholding of the commission's rerouteing of the march.
"In the final phase we deal with the aftermath, with the security scale-down and further monitor the situation," he added.
However, Mr White stressed he would not solely concentrate on Portadown while drawing up plans for the weekend.
The Irish Times Breaking News service will carry up-to-date reports from Drumcree over the weekend at: www.ireland.com