For generations, it has been one of the best perks of the Foreign Secretary's job – a 13th century country estate at the their disposal to woo dignitaries and impress friends.

But it seems hopes of Chevening House being used by Boris Johnson any time soon have been dashed after its trustees refused to hand over the keys.

Mr Johnson has effectively been locked out of the residence in Sevenoaks, Kent, for months because of a dispute over how to share the Grade I-listed property with two other cabinet ministers, The Sunday Telegraph understands.