A man accused of carrying out a racist attack at a firm of immigration lawyers has additionally been charged with preparing an act of terrorism in relation to the alleged incident. Cavan Medlock, 28, from Harrow in north-west London, allegedly visited the offices of Duncan Lewis Solicitors in Harrow armed with a large knife and threatened to kill a member of staff last month. The prosecution alleges Medlock planned to take a solicitor hostage and display flags of Nazi Germany and the US Confederacy in the firm’s office windows to inspire others to carry out similar offences. He allegedly blamed lawyers at the firm for preventing the removal of immigrants from the UK. Days earlier the home secretary, Priti Patel, had claimed activist lawyers were frustrating the removal of refused asylum seekers from the UK. Medlock is charged with six offences including the charge of preparation of an act of terrorism, racially or religiously aggravated attacks against two members of staff at the law firm, and threats to kill. He previously appeared before the Old Bailey by video link from Wormwood Scrubs, but owing to his behaviour on the feed he was barred from Friday’s proceedings. He has yet to enter a plea to the charges. Adam Harbinson, prosecuting, told the court at an earlier hearing that Medlock allegedly told the police he had planned to take a member of staff hostage and place the flags in the window so that like-minded people would take action. On Friday Medlock’s counsel, Graham Arnold, raised no formal objection in court to the terrorism charge being added. Medlock was further remanded in custody. After the alleged attack, Duncan Lewis wrote to the Law Society asking it to contact the home secretary and the lord chancellor “to ensure that attacks on the legal profession are prevented from this point forth”. It added: “The position as it stands is untenable, dangerous and cannot be allowed to persist.”