If required to do so under the Online Safety Bill, WhatsApp says it would rather be blocked in the UK than undermine its encrypted messaging system.
Its CEO, Will Cathcart, stated that if asked to compromise the privacy of encrypted messages, he would refuse.
Signal had previously stated that it would cease providing services in the UK if the bill required it to scan messages.
According to the government, it is possible to have both privacy and child safety.
According to communication regulator Ofcom, WhatsApp is the most popular messaging platform in the UK, with more than seven in ten adults who are online using it.
End-to-end encryption scrambles messages so that even the service provider cannot read them.
However, critics of the Online Safety Bill claim that it gives Ofcom the authority to require private encrypted messaging apps and other services to use “accredited technology” to detect and remove child-abuse content.
Mr Cathcart stated that undermining the privacy of WhatsApp messages in the UK would affect all users.
“Our users all over the world want security – 98% of our users are outside the UK, and they don’t want us to lower the product’s security,” he explained. And the app would prefer to be blocked in the UK.
“For example, we were recently blocked in Iran. That has never happened in a liberal democracy “He went on to say.