The law firm trying to remove Hamas from the UK’s list of proscribed terrorist groups is being investigated by a solicitors’ watchdog, The Telegraph understands.

Riverway Law made headlines in April when it launched an appeal to have Hamas taken off Britain’s list of proscribed groups.

The firm made a submission to Yvette Cooper, the Home Secretary, arguing that Hamas posed “no threat to the UK people” and should be allowed to operate here on free speech grounds.

Just days after submitting its appeal to the Home Office, the firm was reported to the Solicitors Regulation Authority (SRA) by Robert Jenrick, the shadow justice secretary.

Mr Jenrick argued that Riverway’s appeal potentially breached UK sanctions rules on terror groups. He also drew attention to apparent social media posts about the war in Gaza by Fahad Ansari, the leading lawyer in the case and the director of Riverway.

The posts included claims that Hamas is a “legitimate resistance movement” protecting Palestinians from “UK-sponsored Israeli genocide”.