The drugs minister has been accused of a “massive conflict of interest” after it emerged that her husband operates Britain’s largest cannabis farm.

Victoria Atkins has now stopped speaking for the government on cannabis and other aspects of her drugs brief. The Home Office said she had “voluntarily recused herself from policy or decisions relating to cannabis”.

Her husband, Paul Kenward, is managing director of British Sugar, which last year started growing substantial amounts of marijuana in Wissington, Norfolk, under a licence from the Home Office, the department at which she is a minister. The crop covers an area equivalent to 23 football pitches.

Growing the drug is normally illegal, with a penalty of up to 14 years in prison. However, Kenward’s crops are for