Rishi Sunak has denied he's trying to stop WhatsApps being handed to the Covid Inquiry as he's embarrassed about what his own messages contain.
The Cabinet Office is going to court to challenge a request for the government to provide Boris Johnson's unredacted messages from during the pandemic.
But the former PM's allies have accused ministers of seeking a judicial review to set a precedent as they do not want to hand over the contents of their own phones.
Speaking on a trip to Washington, Mr Sunak was asked by the BBC whether he was worried about something embarrassing him.
He said: "No, not at all. I am cooperating and providing information to the inquiry.
"It's actually taking a lot of my own time, but that's right that I do that. But obviously there's a legal proceeding ongoing on one particular thing at the moment, which I can't comment on, but more broadly, the work that the inquiry is doing is important and necessary, and those involved should cooperate in a spirit of candour and transparency. That's what I'm doing and that's what the government's doing."
Asked whether he was happy for all messages to go forward to the inquiry without black marks being put through them, he replied: "As I've said, it's important for me and others to cooperate with the inquiry in a spirit of candour and transparency.
"That's what I'm doing. And I'm spending a lot of my time on it because it is important that we learn the lessons of Covid. Beyond that, because of the legal proceedings that are ongoing. I can't comment any further."
Mr Sunak added: "I think the work the inquiry is doing is important and necessary. It's right that we learn the lessons of Covid so that we can be better prepared for the future. And in that spirit, the government has cooperated with candour and transparency.
"The government has handed out and handed over over 55,000 documents so far with more to come. So I think that demonstrates the seriousness with which the government is taking this.
"Now there is one particular issue on which there is a difference of opinion and that's subject to legal proceedings so I can't comment on that further. But more broadly, the government is demonstrating strong cooperation with the inquiry as the provision of 55,000 documents is evidence of."
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