The number of new pupils due to start at the Holy Cross girls' school in Ardoyne, north Belfast, has fallen by a third following last year's loyalist protest.
Father Aidan Troy, chairman of the board of governors, confirmed numbers were falling. Despite the fact that the picket was suspended last year, recent street violence meant tensions in the area were at an all-time high, he said.
A massive police and British army presence was needed to escort pupils to school after loyalist protesters from Glenbryn demanded they take another route. The picket was called off after the Glenbryn residents received assurances over security and economic measures from the authorities.
Father Troy said he hoped there would be no repetition of the protest this year. However, there have been regular clashes between loyalists, republicans and the police over the summer months.
The INLA shot a Protestant teenager standing on the peaceline in Glenbryn and there have been several gun attacks on Catholics nearby. "Now that the guns have come out on to the streets, the temperature has been raised quite significantly," Father Troy said.
He hoped it would be a peaceful term and that Holy Cross and all the other local schools could "return with minimum attention".
"With the drop in enrolment, we need a calm year to show parents who are nervous that we have conquered this problem and the people of Glenbryn will stand aside from this. I am optimistic that we have the possibility of having a good year but there are worrying clouds there.
"With the recent constant violence, it is clear that if this year does not go well, we are not back to square one, we are a lot worse. We will have slipped into the gutter. Time does not stand still. Relationships unravel and children are forced into therapy." He claimed Holy Cross pupils had been failed by politicians in the Northern Ireland Executive and at Westminster. "The local politicians on the ground have tried to calm the situation with which we have had very little help from Tony Blair or the MP for the area, Nigel Dodds."
He said the school's future depended on the Executive's decision on Glenbryn residents' demands for a peace wall along part of Ardoyne Road, realigning the route walked by pupils. "If the wall is built, the school closes. It is as simple as that."