Boris Johnson will not be restricted over what he can tell the Covid inquiry, a senior minister has said.

But, MP Robert Jenrick insisted it would not be “sensible or reasonable” to hand over ministers’ documents or messages deemed irrelevant to the pandemic as the Government takes the official investigation to court.

It comes after the former Prime Minister was warned he could lose public funding for legal advice if he tries to “frustrate or undermine” the Government’s position.

Cabinet Office lawyers wrote to Mr Johnson, warning that money would “cease to be available” if he breaks conditions such as releasing evidence without permission.

Mr Johnson has been at the centre of a row as ministers launched a High Court bid to challenge the inquiry’s demand for his unredacted WhatsApp messages and notebooks.

He vowed to send all his messages to the official investigation directly, circumventing the Cabinet Office. He has had legal advice paid for by the taxpayer, but the Sunday Times detailed the letter from lawyers containing the warning to the ex-PM.

Mr Jenrick insisted it was “entirely up to the former prime minister how he co-operates with the inquiry”.

The Home Office minister told Sky’s Sophy Ridge on Sunday: “If he wishes to send his documents or WhatsApp messages to them then he’s at liberty to do so.

“He can advance whatever arguments he wants to and make whatever statements he wishes in his witness statement to the inquiry.

“There’s no sense that the Government will restrict what Boris Johnson wants to say, but if you use taxpayer funds obviously you should make sure you’re using them appropriately.”

Mr Johnson is at the centre of the row but the Government is trying to avoid needlessly handing over what it sees as irrelevant messages from other ministers, which