As World Book Day approaches, the financial cost of costumes to celebrate the event can be a concern to some parents.

But some schools are letting children wear pyjamas to represent bedtime stories and suggesting simple costumes.

One head teacher said the day should be accessible to everyone and free books are provided for those who want to read to their children at the school.

Some parents say the plan is a great idea.

At Miskin Primary in Mountain Ash, the school council wanted to “make it as fun as possible, but not put any financial burden on those who can not afford it”, said head teacher Fran Davies.

She said children “could come in jeans and a jumper, they could come in uniform with some make-up on like they were at St Trinians. Some may come dressed as wizards like they’re at Hogwarts”.

Pupils are encouraged to bring their favourite book to school, but the headteacher said she recognises that not all children have books at home.

She said they regularly take children to the library, but there is also a box that offers free books to families who want to read with their children.

Pupil Amelia said: “If you have some old books that you’ve grown out of you can put it in the book box.”

Leah, whose daughter goes to the school, said this year will be much simpler because she is planning to be Hermione from Harry Potter.

“She’s just wearing a school skirt and a school shirt so no extra money and we bought her a wand from a charity shop, and that’s her done.

“We’re crimping her hair with tongs that we already have in the house. Long socks and a pair of Black shoes and she’s Hermione.”

“She’s a massive Harry Potter fan, but if we went out to buy something, the cloak alone would be £20,” said Leah.

Another parent, Kelly, whose nine-year-old is at the school, said: “It’s a really good idea.

“The fact that they can come in pyjamas rather than going out and buying silly expensive dresses or outfits – this is good for our pockets.

“Every child has got a pair of pyjamas or a pretty dress or even school uniform for Matilda,” she added. “Something really simple, and it’s good for them to enjoy books.”