'The doctrine of collective ministerial responsibility requires that all ministers, and usually parliamentary private secretaries, must accept Cabinet decisions, or dissent from them privately while remaining loyal to them publicly, or dissent publicly and resign, unless collective responsibility is waived by the Cabinet on any given occasion. If a minister does not resign over an issue of policy or procedure he will be collectively responsible for it, in the sense that he will have to support it publicly through his votes in Parliament and through his speeches.'
R Brazier Constitutional Practice (2nd edn Clarendon Press Oxford 1994)