The man accused of killing Batley and Spen MP, Jo Cox, declined to respond when asked if he is guilty during a video link appearance at a court hearing this week.
53-year-old Thomas Mair is accused of shooting and stabbing Ms Cox as she arrived for a meeting with residents in Birstall on 16th June.
The murder shocked the country and forced the suspension of British referendum campaigning for several days as people mourned the death of the politician.
Ms Cox had been campaigning for Britain to remain in the EU when she was attacked by Mair.
The case is being treated as a terrorism matter, while Mair is charged with murder, causing grievous bodily harm, and possession of a firearm and a dagger.
His trial is scheduled to begin on 14th November.
During his video link appearance, Mair was seen bearded and wearing a grey sweatshirt and brown trousers. He only spoke to confirm his name and that he could hear the proceedings.
When asked if he pleaded guilty or not guilty to the charges, he remained silent.
Judge Alan Wilkie therefore said: “He appears to be mute therefore I will enter a plea of not guilty.”