The bill would criminalise watching online content likely to be useful for terrorism, even if viewed with no terrorist intent. The offence would carry a prison sentence of up to 15 years. It would make the work of investigative journalists very difficult.

The bill would criminalise publishing (for example, by posting online) images of clothing or an article such as a flag in a way that aroused “reasonable suspicion” that the person doing it was a member or supporter of a proscribed (terrorist) organisation.

The bill would introduce new border security measures that would not allow journalists to protect sources and confidential materials.

The bill will be considered in the House of Lords on 9 October.

Index is an official partner in the Council of Europe’s Platform for the safety of journalism.

Joy Hyvarinen, head of advocacy said: “Index considers this bill to be a threat to media freedom in the UK, which is why we have alerted the Council of Europe. It is extremely important to tackle terrorism, but doing it by undermining media freedom is not the right way. Journalists must be free to do their work.”