Government officials sent an email on Friday detailing the plan for an investment summit that kicks off Monday. The conference has a guest list of business and policy leaders the U.K. is trying to woo in a bid to boost its investment case. 

But the note cc’d business leaders, including LVMH’s CEO Arnault and others, and was visible to all recipients. 

The government apologized for the slip-up, saying it was “an administrative human error.”  

“We take data protection very seriously, and we have referred this issue to the Information Commissioner’s Office,” a spokesperson for the Department for Business and Trade (DBT) said in a statement to Fortune. 

DBT declined to comment on the number of recipients of the email. 

An ICO spokesperson told Fortune: “We received a report from the Department for Business and Trade after an email was sent without using blind carbon copy [bcc]. After reviewing the information provided, we provided data protection advice and closed the case with no further action.”

Arnault is one of the most influential people in Europe. His LVMH luxury empire is worth €318 billion and is considered a bellwether of the fashion industry. 

The stakes couldn’t be higher for the U.K. in the lead-up to today’s investment summit, which is meant to be Prime Minister Keir Starmer and his government’s pitch day to investors. The event has attracted high-profile business personalities, including former Google CEO Eric Schmidt and Universal Music Group executive Lucian Grainge. There were also some A-list exclusions like Elon Musk.

Reports suggest that some attendees are frustrated with the lack of information since the conference happens just weeks before the Labour Party’s budget reveal, expected to include tax hikes. Starmer’s leadership has also been on shaky ground: His top team has been overhauled, and the party’s popularity has plummeted since Starmer’s election. 

The investment summit can be an opportunity to prop up the government’s efforts to attract foreign capital. Last year, for instance, former Prime Minister Rishi Sunak unveiled £29.5 billion in private-sector investments for the U.K. 

In the ongoing event, Starmer has announced paring back regulations to incentivize investors and drive home the message that Britain is “open to business.” 

An EY report earlier this year reported that although continental Europe was struggling to attract business following the pandemic, London and the U.K. were faring well compared to their rivals.

However, a blunder like leaking confidential email IDs, such as Arnault’s, could not help Britain’s case just as the government is trying to get more businesses excited about them. Whether the U.K. has a strong enough case beyond the turbulence remains to be seen.