Starmer told a press conference that "no options are off the table" when asked about restricting social media for younger people, adding he was also concerned about the amount of screen time for young children.

Politicians in Britain, France and elsewhere are mulling restrictions after Australia last month became the first nation to prohibit under-16s from using social media platforms such as Instagram, Facebook, TikTok and YouTube.

"I think we need to do more to protect children, and that's why we're looking at a range of options and saying that no options are off the table," said Starmer, who is reportedly awaiting more evidence from Australia's ban before considering similar restrictions.

Some 60 MPs from Starmer's Labour party wrote an open letter on Sunday, urging the prime minister to change tack and block access for under-16s over concerns about the harms to young people's mental health.

"Successive governments have done far too little to protect young children from the consequences of unregulated, addictive social media platforms," the lawmakers said.

Leader of the opposition Conservative party Kemi Badenoch also urged Starmer to go further on the issue and back a ban.

"I want Keir Starmer to do a U-turn -- and ban Britain's under-16s from social media," Badenoch wrote in the Mail on Sunday.

A cross-party amendment for a ban similar to Australia's will likely be voted on this week in the House of Lords -- Britain's upper house of parliament -- according to UK media.

Across the Channel, France is currently debating bills for a social media ban for under-15s, including one championed by President Emmanuel Macron.