Media playback is unsupported on your device Media caption JoJo Siwa tells CBBC Newsround about her love of hair bows

Some UK schools are banning pupils from wearing "JoJo bows", giant hair clips that have gained popularity thanks to a teenage dancing YouTube star. So why have the bows become so big?

Parents of primary-school age children may have noticed them in the playground: massive colourful bows young girls are wearing atop a ponytail or bun.

Several schools say the bows breach uniform policy, leaving parents divided over whether their children's JoJo bows should be allowed.

Among them are Sawley Junior School in Nottinghamshire and Fairfield Community Primary in Bury, Greater Manchester, with the head teacher there, Chris Ashley, describing the bows as "distracting".

Why the 'big bow' craze?

At around £8 to £12, the ruled-out ribbons aren't cheap.

But they are the signature bows worn by 13-year-old social media star JoJo Siwa, a dancer and singer from Nebraska in the US.

"I've always just worn bows" JoJo told CBBC's Newsround.

"They just got bigger and better and sparklier - and then I became 'JoJo with the bow bow' and it became a thing."

JoJo sells a line of bows at Claire's Accessories, a chain popular with tweens in Britain as well as the US, which has been available since last May.

Several independent retailers have also sprung up with imitation bows.

Image copyright Claire's Accessories Image caption JoJo's bows can be found on nearly every UK high street

Michelle O'Shaughnessy, who owns a craft shop in Cradley Heath near Birmingham, began selling homemade bows in February and says the trend has "started to spread".

She said: "My daughter loved the JoJo Siwa bows but they're so expensive, so I decided to make my own, and people got interested."

Retailers have cottoned on to schools' dislike of the garish bows, with Claire's stocking JoJo bows in red, white, navy and black to keep them in uniform colours.

'Chop them to pieces'

Parents and teachers have taken to social media to ask: "How big are the bows at your school?"

One teacher posted on the Mumsnet forum: "There are loads of girls wearing these bows. My daughter is wearing one now because she has a birthday party later but she doesn't wear it to school."

Image copyright Michelle O'Shaughnessy Image caption Some retailers are selling 'copycat' JoJo bows

Another claims her daughter, 10, "spent ALL her Christmas and birthday money - over £100" on bows.

"I'm tempted to chop them to pieces in the middle of the night and claim ignorance," she adds.

Others see the bows as an 80s throwback or say they have long been popular with children who dance or do gymnastics.

'Fair game' to ban bows?

Schools have a right to ban bows if they breach uniform policy and teachers can ask pupils to go home if they break the rules, according to guidelines set by the Department for Education.

Francesca De Franco, a mother-of-three who founded The Parent Social forum, says it is "fair game" for schools to ban bows.

"They're trickier to ban if they're in school colours, but some of these bows are absolutely enormous," says Surrey-based Francesca.

"My daughter's school hasn't banned them yet but it had similar problems with Pokemon cards, when the children began swapping them and some went missing."

Image copyright @missmcracken Image caption One primary school teacher notes the 'contagious' craze for big bows

Parent Zoe Dudley said on Facebook that "it's so sad" that the bows were banned in her daughter's school.

"Really what's the problem? Next it'll be bob cuts for girls and skin head boys," she says.

But science teacher, Alex Aveyard, tweeted that "uniform is important... They shouldn't be worn in school especially if they aren't school colours!"

For her part, JoJo says "it's a very bad thing" that some schools weren't letting pupils wear bows.

But she advises fans: "Follow the rules, it's very unfortunate if your school is banning them."

Who is JoJo Siwa?

A dancer, singer, reality TV and social media star - JoJo Siwa hasn't yet reached her 14th birthday but she has 3.7 million followers on YouTube.

JoJo gained fame on the US TV series Abby's Ultimate Dance Competition in 2013 and later appeared on Dance Moms, a reality show she left last year.

Image copyright EPA

She regularly posts videos on how to accessorise and make hair bows and has released an online song called Boomerang, which deals with online bullying.

The JoJo bow, she says, is "more than just a hair accessory, it is a symbol of power, confidence, believing-ness."

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