Facebook’s plans to encrypt its services will lead to more children being sexually abused online as its boss Mark Zuckerberg puts profits and secrecy above safety, the head of the NSPCC warns on Monday.

Peter Wanless said the company, which has 1.3 billion users, was cynically going ahead with the plans even though it knew they would lead to more children being groomed and sexually abused.

"It betrays very obviously their misplaced priorities," he said in an exclusive interview with The Telegraph in advance of Tuesday's annual NSPCC conference which will focus on online child safety.

Figures, revealed on Monday, show more than 1,500 children as young as 12 called Childline last year as potential victims of online grooming or sexual abuse, a 19 per cent increase on 2017.

The charity is backing The Telegraph’s campaign for a new statutory duty of care on social media firms to better protect children from online harms.