Far-right anti-migrant activist Daniel Thomas, also known as Danny Tommo, has been remanded in custody ahead of a trial next year.
Thomas was arrested last week after footage livestreamed online appeared to show him taking a knife to an inflatable dinghy when a French coastguard official was on board.
He was subsequently charged with criminal damage and failing to disclose the PIN to his phone, charges he has pleaded not guilty to.
The 37-year-old is accused of accused of criminal damage to a boat in the English Channel and appeared at Portsmouth Crown Court on Tuesday morning.
Appearing via vide0link from prison, Thomas was denied bail by Judge James Newton-Price KC and remanded in custody, Sky News reports.
A provisional trial date has been set for 1 March 2027.