Fe'u penodir gan y Prif Weinidog i helpu Gweinidogion i ymateb i faterion pan fo gwaith y Llywodraeth a'r blaid sy'n llywodraethu yn gorgyffwrdd a phan na fyddai'n briodol i weision sifil parhaol gymryd rhan. Maent yn adnodd arall i'r Gweinidog ac yn rhoi cefnogaeth a ddaw o safbwynt sy'n fwy ymroddedig ac ymwybodol yn wleidyddol nag y byddai modd i'r Gwasanaeth Sifil parhaol ei gynnig i Weinidog.
They are appointed by the First Minister to help Ministers on matters where the work of Government and the work of the Government Party overlap and where it would be inappropriate for permanent civil servants to become involved. They are an additional resource for the Minister providing assistance from a standpoint that is more politically committed and politically aware than would be available to a Minister from the permanent Civil Service.