British private schools are renowned around the world with thousands of children coming from overseas to attend them. But, like in the U.S., education prices are going up and may be about to go up a lot more.

The average cost of sending your child to a private school in the U.K. is around $18,000 a year. For that, you get small classes, better facilities and a broader range of subjects. Giannis is 11 and recently moved from a state elementary school to a private one.

“We did a lot more,” he said. “We did STEM, which was a subject I was new to. We also did Latin in our year six.”

Giannis struggles with dyslexia, and his mother, Maria Halepi, said she felt she had no choice but to pay the $11,000 in annual fees.

“When COVID happened, it turns out that you had massive gaps and the school wasn’t doing anything really to catch him on,” she said.

Now, Halepi said her son is caught up and much more confident — and she thinks it was worth finding the cash.

“It didn’t come as spare money. We worked so hard,” she said. “We’re not into cars or anything or lavish holidays, but it was the best money we’ve ever spent for our son.”

Other parents are making similar decisions to switch, particularly after homeschooling during the COVID pandemic left children struggling or with learning gaps. At the other end of the scale are the children of celebrities and the rich, who go to elite private schools like Eton College.

But some people think it’s unfair you can buy a better education — including Labour, the main opposition party in the U.K. They want to undo a tax exemption private schools have enjoyed for decades.

“What we’ve got at the moment is an extremely uneven playing field with vast amounts of financial resources going into 7% of the population. And that’s really economically inefficient,” said professor Rebecca Boden, an expert on private school finances and a Labour supporter.

The extra tax would raise around $2 billion for public education, but it might also add an extra 20% to school fees. One think tank estimates 3% to 7% of pupils might be forced to leave.

Jane Lunnon, who runs Alleyn’s School, a private school in London, argued that this won’t affect the rich.

“Parents who are working hard — really making sacrifices in order to invest in their children in this way,” she said, “they’re the people who will get hit by this.”

Ewan King, whose son is at a private elementary school, agrees. “For us, it would probably push us over — our ability to be able to afford his school fee,” he said.

For now, private schools get to keep their tax break. But if the opposition Labour party wins the general election next year, the price of private education will almost certainly go up.