Belfast residents have appealed for calm amid fears a major Protestant march today could result in disturbances on the streets.
Although a compromise arrangement has been laid down to ensure Orange Order members show respect while parading past a Catholic church, all sides are aware trouble can erupt from small incidents.
Up to 30,000 people are expected to join the Ulster Covenant centenary commemoration march.
"There's an awful lot of apprehension," a Catholic shopkeeper said. "Our local community is disgusted with the whole thing. And we can see that the Protestants are extremely annoyed – they think marching is their God-given right."
The Northern Ireland Secretary Theresa Villiers said huge efforts had gone into dialogue but added: "I think everyone is nervous."
Last month seven police officers were injured in violence after loyalist bands defied a ruling not to play music as they passed by St Patrick's Catholic church.
Orange leaders have had "quiet conversations" with the local parish priest, though there have been calls for them to go further and talk to local residents. The Order has volunteered to ensure bands play hymns rather than tunes which might be regarded as offensive.