asked the Minister of Production whether it is the established practice of all departments associated with production that development work on mechanical equipment must be a continuous process and that until a machine has been built and tried out it should not be put into production?

Yes, Sir, whenever practicable; but my hon. Friend will appreciate that operational and other war-time exigencies sometimes make necessary a departure from the established practice referred to.

In cases where development and production have been elided has this practice not led to undue delay in the production of satisfactory equipment?

Risks sometimes have to be taken.

Is it not a fact that two years ago a stop was put to the development of tanks and aeroplanes and that that is one of the reasons why we fell behind in aeroplanes and never got a satisfactory tank?