Radical preacher Anjem Choudary will appear before the Old Bailey later to answer to a charge of encouraging support for Islamic State on social media.
The 48-year-old married father-of-five will be brought from custody to enter his plea alongside his co-accused Mohammed Rahman.
They are both charged with inviting support for the banned terror group Isil, also known as Isis or Islamic State, between June 29, 2014, and March 6, 2015.
Choudary, of Hampton Road, Ilford in east London, and Rahman, 32, of Sidney Street in Whitechapel, east London, will appear before Mr Justice Holroyde from 12pm.
They are expected to go on trial on January 11 at a London court to be decided and the case is scheduled to take up to four weeks.
Both men were granted bail with strict conditions in September, but last month Choudary had it revoked and was sent back to jail to await trial.