Michael Gove has concerns about Boris Johnson becoming the leader of the Conservative party, a leaked email from his wife appears to suggest.
Sarah Vine, who is married to Mr Gove, appears to have accidentally sent the message intended for her husband to a third party.
The emailed, which mentions Mr Gove seeking “specific assurances” from Mr Johnson, was then passed to the broadcaster Sky News.
In it, Ms Vine notes that her husband’s support would “not be guaranteed”, for Boris and that he should make this clear to the former Mayor of London.
She says Mr Gove’s support would be useful to Mr Johnson for gaining the endorsements of Rupert Murdoch, who owns The Sun and The Times newspaper, and Paul Dacre, the editor of the Daily Mail.
It reads: “Very important that we focus on the individual obstacles and thoroughly overcome them before moving to the next. I really think Michael needs to have a Henry or a Beth (Mr Gove's media advisers) with him for this morning's crucial meetings.
“One simple message: You MUST have SPECIFIC assurances from Boris OTHERWISE you cannot guarantee your support. The details can be worked out later on, but without that you have no leverage.
“Crucially, the membership will not have the necessary reassurance to back Boris, neither will (Daily Mail editor Paul) Dacre/(Rupert) Murdoch, who instinctively dislike Boris but trust your ability enough to support a Boris Gove ticket.
“Do not concede any ground. Be your stubborn best.
A spokesperson for Mr Gove told the broadcaster: “We don't comment on private email exchanges or conversations.”
Mr Johnson is the bookies’ favourite to be the next leader of the Conservative party but has yet to officially announce his candidacy.
He is running in the replace to replace David Cameron, who stepped down after losing the European Union referendum, which he called.
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