PARENTS are up in arms after their kids were not allowed to enter school - until they showed they had a GREEN PEN.

Children were left outside in the pouring rain for up to 45 minutes this morning while their bags were searched to make sure they had the "vital" piece of equipment.

Those who did not have a green pen in their pencil cases were told they could buy one for 20p - or be turned away from school.

A green pen is part of a student's required equipment at Park Lane Academy in Halifax, West Yorkshire, and is used to mark their own work.

But several parents expressed their disgust on Facebook after getting phone calls from their kids telling them they weren't allowed in school and needed picking up.

Others who arrived at school were rowing with staff and teachers.

One parent, who had arrived at school early for a meeting and did not wish to be named, described the scenes as 'chaos' and claimed the school had lost control of the situation.

She said: "It was ridiculous. There were dozens of children just stood out in the rain. It was cold and many of them didn't have coats with them.

"As I left the school there were kids standing at the bus stop, walking home, there were parents shouting at staff.

"They just had absolutely no control over what was going on. It was awful."

One mum wrote on Facebook: "My daughter just phoned me. Head teacher going through their pencil cases.

"Said they're not allowed in school if they don't have a green pen and having to stand outside. Absolutely fuming."

Another said: "My son rang me panicking cos he doesn't have a green pen."

While another said: "It's absolutely pathetic 'cos we don't know if our kids are in school."

Shortly after 11am, parents received a message from the school's Principal Miss Lisa Corrigan, which said: "Following the slow start to this morning's lessons we will be amending the morning procedures.

"As of tomorrow, different year groups will enter through different doors in order that uniform and equipment is checked more quickly.

"All students will be given a green pen today free of charge, but we ask that you maintain talking to your children about being organised for school."

The school said helping students become more organised and prepared for learning has helped it improve results.

Lisa Corrigan, principal of Park Lane Academy told The Sun Online: “Following equipment checks this morning, students were asked to queue so their heads of year could give them equipment and speak to them regarding being prepared for learning.

"All students were given green pens today to respond to feedback from teachers in their exercise books. Parents received a text message about equipment.

"The school entry procedures have also been amended in order to allow students into school more quickly.

"No children were sent off-site or told they would not be allowed entry into the premises.”