SMMT chief executive Mike Hawes said June’s figures “demonstrate the risks of judging automotive performance one month in isolation, with numerous and varied factors creating a perfect storm for home market output”.
More than eight out of ten cars made in Britain are exported and the SMMT said that this had continued to drive production with overseas orders helping to “bolster disappointing domestic demand”.
It said overseas orders were “broadly stable” in the first half of this year, meaning car production was down just 3.3% for the first half of the year.
But Mr Hawes said the reliance of the UK market on exports demonstrated the importance of the industry’s “dependency on free and frictionless trade”.
He said any disruption to this due to Brexit “risks undermining” this.