A man who threatened Alexander Pechtold, the leader of the social democratic party D66, on Facebook has been jailed for one week by the appeal court in Leeuwarden.

The 51-year-old from Groningen placed the threat – a photograph of a gun with the text ‘Pechtold, you need to be shot in the head’ – on the social media network in September last year.

The suspect was found not guilty by a lower court earlier this year on the grounds there was no reason to think the man would actually carry out his threat. The appeal court disagreed, saying Pechtold could have feared the man might attack him.

Pechtold said the decision to jail the man sent out an important signal to people who make threats. ‘We must not come to think it normal to threaten people with death,’ he said. ‘I have drawn the line.’