Thomas Mair will appear in court Monday charged with the murder of Labour MP Jo Cox and may apply for bail.
Cox, 41, died after being shot and stabbed in the street outside her constituency surgery in Birstall, near Leeds, on Thursday.
Mair, 52, from Birstall, will appear at the Old Bailey charged with murder, grievous bodily harm, possession of a firearm with intent to commit an indictable offence and possession of an offensive weapon.
At an initial hearing at Westminster Magistrates' Court on Saturday, Mair refused to give his name, instead saying he was called "Death to traitors, freedom for Britain".
Mair was not required to enter a plea and his lawyer Keith Allen said there was no indication what plea would be given.
The hearing is expected to consider any application for bail.