The Treasury Select Committee has sent a formal notice to HM Revenue & Customs demanding answers to critical questions about how it has been enforcing trade sanctions on Russia, following a Sky News investigation into the government department.

Last month Sky News reported that while HMRC had issued six fines in relation to sanction-breaking since 2022, it would not name the firms sanctioned or provide any further detail on what they did wrong. HMRC also admitted it had no idea how many investigations it was currently carrying out into sanction-breaking.

The admissions raised questions about the robustness of Britain’s trade sanctions regime, described by government ministers as the toughest in British history.

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While the UK has introduced rules preventing the export of certain goods to Russia, banned items are still flowing into the country via third countries in the Caucasus and Central Asia. Some suspect that part of the reason these flows continue is that HMRC is not enforcing the rules as robustly as it could be.

Following Sky News’ investigation, the chair of the Treasury Select Committee (TSC), Dame Meg Hiller, has written a letter to the chief executive of HMRC, Sir Jim Harra, with 10 questions about HMRC’s conduct in the enforcement of sanctions.

Among the questions, the TSC chair asks: “Why doesn’t HMRC publish information on breaches in sanctions in a similar way to the Office for Financial Sanctions Implementation (OFSI), which gives the details of the company, how it breached sanctions and the amount of penalty issued?”

Many other countries around the world – most notably the United States – routinely “name and shame” those who break sanctions, in part as a deterrent and in part to inform other businesses about what it takes to break the rules. But HMRC instead protects the privacy of those who break sanctions.

The TSC has been scrutinising the sanctions regime in recent months, examining loopholes in the legislation and its enforcement. HMRC has been asked to respond to the letter by 17 February.