Queen Elizabeth II has given royal approval to a law that will make it illegal in England and Wales to take "upskirting" photos. The law, which takes effect in April, makes it a criminal offense to take pictures under a person's clothes without permission.

It is the result of a campaign started by Gina Martin after a man placed a phone between her legs and took a picture of her at a London music festival in 2017. She reported the incident to police then discovered the man didn't break any law, BBC News reported.

Martin said Tuesday the welcome change was a "long time coming."

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The bill had the backing of Prime Minister Theresa May, who praised activists advocating for a change in legislation.

"Very pleased to see the degrading practice of upskirting become a criminal offence after the tireless work of victims and campaigners," May tweeted after the bill received final approval in Parliament.

Once the law goes into effect, authorities will be able to arrest people suspected of upskirting, according to the BBC. Lawbreakers risk being jailed for two years and being put on the sex offenders register.