The authorities will be hoping that major confrontations can be averted on what is one of the last potential major flashpoints of the loyalist marching season. But the season is tailing off on an unpromising note in that, despite talks between loyalists and Catholic residents in both cities, no agreement was reached on either parade.
In the absence of agreement, the go-ahead for the two marches was imposed by the Northern Ireland Parades Commission. The Belfast parade is what is known as a feeder for the main event of the day, the loyalist celebration of the relief of the siege of Derry in 1689.
The Belfast parade is to take place through the Catholic lower Ormeau district, a contentious area from which most loyalist marches have been barred in recent years. Local Catholics said they would stage protests which would be "dignified, peaceful but determined."
They added that an attempt to block the route was a possibility, and their critics pointed out that they had not promised their activities would be lawful.
This uncertainty guarantees large numbers of the security forces will be on hand to police the march. In Londonderry the Parades Commission intervened following days of unsuccessful negotiations to allow a limited march by the loyalist Apprentice Boys of Derry around the city's walls.
The commission restricted the number of bands allowed on the walls from eight to one and asked participants to comply with a number of conditions.
This brought immediate protests from local Catholics, with Bogside Residents' Group spokesman Donncha MacNiallais describing the decision as "reckless and ill-judged."
He said there were suggestions of blocking one of the city's main arterial routes, the Craigavon bridge, but a decision on what form of protest would be taken later.
He added: "We will make every effort to act responsibly. This situation requires cool, calm disciplined heads, but it won't be easy. I fear a major crisis and possible violence."
The Apprentice Boys Governor, Alistair Simpson, claimed that threats had been used to try to hold his organisation to ransom.
He said: "I am profoundly disappointed that once again the veiled threat of violence has been used as the means of holding the Apprentice Boys and this city to ransom."Reuse content