asked the Minister of Transport what percentage of diesel engine vehicles stopped by his Department's examiners have been found to be emitting an unacceptable amount of noxious smoke.

This information is not available. It would have little significance, as many of the vehicles were stopped because they were seen to be smoking excessively. Of about 75,000 diesel vehicles observed during special smoke checks in 1965, nearly 8 per cent. were smoking badly enough to warrant prohibition notices. This compares with a little under 9 per cent. in special smoke checks in 1964.