Social media users could be cut off from other accounts on platforms such as Twitter if they do not sign up for ID verification, under government proposals to tackle anonymous trolls.

The proposals mean online platforms would need to give users a way to verify their identity, and allow them to block any unverified accounts from messaging or replying to them.

The onus would be on tech firms to decide how to carry out identity checks, the government said, adding this could include:

• The option to verify a user's profile picture using facial recognition software.
• Two-factor authentication tech that sends someone a text asking them to verify their identity.
• The requirement for a government-issued ID such as a passport when creating or updating a social account.

This means people or organisations without verified accounts – symbolised by a blue tick on Twitter and Instagram – would be blocked from communicating with, or being seen by, accounts that have opted out from interactions with unverified sources.

The new system will be introduced under the online safety bill, which requires tech firms to protect users from harmful content or face the threat of substantial fines imposed by Ofcom, the communications regulator.

The culture secretary, Nadine Dorries, said: "Tech firms have a responsibility to stop anonymous trolls polluting their platforms." She added: "People will now have more control over who can contact them and be able to stop the tidal wave of hate served up to them by rogue algorithms."

However, the government has ruled out banning anonymity online entirely, acknowledging that it would be damaging for domestic abuse victims, activists living in authoritarian countries or young people exploring their sexuality.

Critics have expressed privacy concerns over the new online safety bill

The ID move was welcomed by the Football Association, which has called for action against racist and abusive online trolls who often operate anonymously.

It's not clear exactly how the latest measures proposed by the government would work. Some campaigners have expressed concern that the bill may limit freedom of expression online.

Critics such as Big Brother Watch, a privacy campaign group, said the proposed change represented another move towards an ID scheme for the internet.

"The government's plans to undermine online anonymity will do untold damage to privacy and free speech rights in the UK. This move towards ID for the internet is unnecessary and will have no discernible impact on the tone of conversations online," Mark Johnson, BBW's legal and policy officer said.