This drop was determined by the fall in car passenger vehicles that slumped an annualised 24.5% even while the output of light commercial vehicle and heavy goods vehicles rose by 32.4% and 9.6% respectively said the statement.

Of the 14,026 passenger vehicles, some 94.8% of national production was due for export that nevertheless fell back 15.1% year-on-year.

In accumulated terms, the first five months of 2016 saw total vehicle production in Portugal of 64,993 units, down 9.8% on the same period of 2015, with 61,696 vehicles exported, down 11%.

The figures came on the same day that the Portuguese Road Accident Prevention Institution released a study showing that almost a half of drivers do not bother indicating before changing direction with men particularly prone to such a habit.

The study observed 1,242 drivers, 895 men and 347 women across 11 Portuguese cities and found that 46.3% of drivers did not bother to flag up their changes in direction.

The study found that women were far more likely to make recourse to the indicator, with 60% of female drivers following the rules against 51% of men.

Both women and men are more likely to signal when turning left, 62% and 55% respectively with those figures dropping to 58% and 46% for right-hand turns.

"It is interesting to note that a large majority of drivers report this failing in communications about other drivers but end up engaging in the same behaviour that they themselves criticise," the study quotes institution president, José Miguel Trigoso, as concluding.