Conservative leader Kemi Badenoch has laughed off being added to a WhatsApp group mistakenly set up by shadow justice secretary Robert Jenrick to promote his London Marathon run.

Hundreds of contacts, including Conservative MPs, peers and political journalists, were among those added to group chat on Thursday morning.

A source said Jenrick had announced he was running in the London Marathon and “in a technical mix-up, a message designed for broadcast turned into a group chat”.

The source said all of the contacts – which are believed to include former cabinet ministers Michael Gove and Therese Coffey – had been removed from the group and the chat had been deleted.

When asked if she had been added to the group chat, Badenoch laughed before replying: “Yes and then no, I think is the correct answer to that.”

“I think he’s running a marathon,” Badenoch added. “I don’t really understand yet what happened with the WhatsApp group.”

The BBC understands Jenrick’s intention was to send messages about his marathon run individually to friends and colleagues in Westminster, in an attempt to raise money for charity.

In a post on X, Reform UK chairman Zia Yusuf said Jenrick had appeared to add “his entire contact book” to the group chat.

“He’s now spending his morning deleting hundreds of them,” Yusuf posted.

In reply to that post, Jenrick wrote: “Feeling left out again, Zia?”

Jenrick said he was running the London Marathon for SSAFA, the Armed Forces charity, adding he was “rallying support for the cause”.

The Conservatives said they had consulted their data protection officer Andy Steadman, who had said this was not a party issue.

“This is nothing to do with the party, its a personal thing for Robert running a marathon,” a Conservative spokesperson said.

The BBC has been told Jenrick is not referring himself to the Information Commissioner’s Office (ICO), which investigates data breaches.

A source said the ICO did not need to be involved because the contacts had been added to the group for “personal purposes” and the risk of malicious use was low.

The BBC has seen screenshots of some of the messages in the group chat.

In one message, a member posted “RJ for PM”.

Badenoch was asked if Jenrick, who previously ran against her for the Conservative Party leadership, now poses a fresh threat to her.

She said: “I have a great team and I’m leading a team that is uniting the Conservative Party.

“And what we’re really focused on now is ensuring that people understand that voting Conservative at the local elections is the only credible option”.