Broken bollards are compromising the safety of primary school pupils, according to a worried parent.

Mark Bliss, of Kingston Road, north Oxford, whose six-year-old daughter attends SS Philip and James Primary School in Navigation Way, is urging highways officers to fix the mechanical bollards, part of a series of road safety measures near the school.

They have broken down repeatedly since their installation a year ago.

In a letter to the county council, Mr Bliss said the rising bollards were not working on January 14, the first day of term, when 330 pupils were united on one site.

He said: "Immature and inexperienced school travellers were being forced to mingle with an under-regulated and indiscriminate number of vehicles going both ways".

Mr Bliss added: "This particular breakdown of these bollards has continued with various interconnected component failures since before Christmas."

Until this month, 125 pupils were forced to remain at the school's old Leckford Road site, while safety measures were completed along the narrow Aristotle Lane bridge, the only access to the new site.

Staff and authorised visitors to the school can use swipe cards to make the bollards retract but parents are not allowed to drive up to the school to drop their children off or pick them up.

Staff in a control centre linked to on-site cameras operate the bollards for those without swipe cards.

Dermot Roaf, county councillor for Oxford North and a governor at the school, said some parents were taking advantage of the broken bollards to pull up outside the school, despite the agreement that this should not take place.

He said: "There are a small minority breaking the rules and it encourages others to follow suit."

Richard Dix, head of highways, said the bollards would be fixed at the earliest possible opportunity.

He added: "I do not feel children's safety is being compromised by this failure."