He’s not an MP, so how can David Cameron return to the cabinet?
The Guardian says To those not fully up to speed with UK politics, the idea of putting someone who retired as an MP seven years ago into a top government job might seem extremely odd. But David Cameron’s elevation to foreign secretary is not without precedent.
How can Cameron be in the cabinet and not in the Commons?
By being made a peer. The Downing Street announcement of Cameron’s job said that the former prime minister was immediately being made a life peer, meaning he will sit in the House of Lords. Theoretically, you can be made a minister without being in either the Commons or Lords, but in practice if a minister is not an MP they will sit in the Lords.