Norfolk MP Elizabeth Truss has been told she will need to share the use of a grace and favour mansion with deputy prime minister Dominic Raab.
Recently appointed foreign secretary, Ms Truss and deputy prime minister Mr Raab had both been keen to make use of the 115-room country house of Chevening.
The property, in Kent, has traditionally been reserved for the foreign secretary.
But Mr Raab sought to retain the use of the property and prime minister Boris Johnson - as first reported by The Times - decided that, rather than risk upsetting one or other of his colleagues, they should share it.
He cited the precedent of the last time there was a deputy prime minister - Sir Nick Clegg - who shared it with then foreign secretary Lord Hague of Richmond and later his successor Lord Hammond of Runnymede.
A government spokesman said: "The deputy prime minister and foreign secretary will share access to Chevening as has happened in previous administrations."
The ruling by Mr Johnson - who has been holidaying in Spain - came after Ms Truss posted a picture on Twitter of herself meeting the foreign ministers of Latvia, Lithuania and Estonia in the grounds of the Grade I-listed building.
Under the terms of the Chevening Estate Act 1959, the house - which is privately owned by a board of trustees - is occupied by someone nominated by the prime minister.
The Guardian quoted a source close to Ms Truss, who said the issue had not been a priority and she was focused on more important things.
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