LONDON, October 7--A proposed drastic revision of Britain's empire life-line defense strategy by shifting key military bases from the Eastern Meditteranean to East Africa was disclosed tonight by an authoritative War Office source.

This source said the British general staff had proposed tentatively the withdrawal of British administrative and supply bases from the Eastern Mediterranean--including Palestine--to the East, African colonies of Kenya and Tanganyika.

This proposal envisioned retention of Britain's forward operational bases as long as practicable in such countries as the Sudan, Palestine, Iraq and Trans-Jordan, the informant said.

Reasons advanced in support of the change include Britain's gradual evacuation of India, her impending departure from Elgypt and the instability of the Palestine situation.

Although Palestine's instability was recognized in a general staff report proposing the change, the informant said there appeared to be little likelihood of a complete withdrawal from the Holy Land