The Commonwealth Prime Ministers' Conference in London, after giving the all clear to Mr. Harold Macmillan's line of Disarmament for the forthcoming Summit, turned to world finance and trade issues on May 4. Authoritative sources said that the visiting statesmen endorsed the British view that general and complete disarmament must be in balanced phases, and that both convention and nuclear disarmament measures must be “policed” through effective international inspection and control. They also backed the efforts being made at the 17-month-old negotiations in Geneva between Britain, the United States and the Soviet Union, to ban nuclear weapon tests.