AGE verification tools required on porn sites to prevent underage internet users seeing explicit content will be introduced in July.

The measures, the first of their kind anywhere in the world, will require porn sites by law to carry out "robust age-verification checks on users", the government has said.

Websites that fail to implement the new rules - which will come into force on July 15 - face having payment services withdrawn or being blocked for UK internet users.

READ MORE: what do the new rules mean?

The government said users will be able to verify their age in a number of ways, including using traditional forms of ID such as a credit card or passport, or by buying an over-the-counter card from shops where verification would take place face-to-face.

Digital minister Margot James said: "Adult content is currently far too easy for children to access online. The introduction of mandatory age-verification is a world-first and we've taken the time to balance privacy concerns with the need to protect children from inappropriate content.

"We want the UK to be the safest place in the world to be online and these new laws will help us achieve this."

The government confirmed that the British Board of Film Classification (BBFC), which classifies movies in the UK, will be the age verification regulator.

Its chief executive David Austin said: "The introduction of age-verification to restrict access to commercial pornographic websites to adults is a groundbreaking child protection measure. Age-verification will help prevent children from accessing pornographic content online and means the UK is leading the way in internet safety.

"On entry into force, consumers will be able to identify that an age-verification provider has met rigorous security and data checks if they carry the BBFC's new green 'AV' symbol."

The announcement follows the publication last week of the government's white paper on Online Harms, which set out new responsibilities for technology companies to keep UK citizens safe online.

Carolyn Bunting, chief executive of online safety group Internet Matters, welcomed the introduction of the new tools.

"We are delighted to see the government tackling the issue of online pornography - as children seeing content they're not emotionally ready for can be very damaging, especially if they don't speak out about it," she said.

"While our research shows that parents overwhelmingly support age-verification and are confident it will make a difference, we must recognise that digital solutions aren't the only answer and parents can't become complacent about their child's digital world.

"There is no substitute to having regular and honest conversations with your child about what they're getting up to online, establishing an open dialogue about their digital life from a young age."

However, campaigners have warned the tools could have consequences for user privacy.

Jim Killock of the Open Rights Group said on Twitter: "#ageverification dangers are obvious, from outing people to ruining careers and even suicides.

"What porn you watch can be very sensitive information. It's striking that MPs don't seem concerned, it's not like public knowledge about watching porn has never impacted an MPs career."

The government said alongside requirements for age-verification providers to comply with the General Data Protection Regulation (GDPR), it had created a voluntary certification scheme, the Age-verification Certificate (AVC), which will assess the data security standards of those services which used to verify age.