There were 124,394 new cars registered across the UK last month, the Society of Motor Manufacturers and Traders (SMMT) said. That was down 20.6 per cent compared with the same month last year.
It was the second lowest number of new cars registered in May since 1992.
Only May 2020 - when the UK was in a coronavirus lockdown - was worse for the industry.
Industry leaders attributed the weak sales outcome to shortages of components which are reducing vehicle availability “despite demand”.
Registrations of pure electric cars bucked the overall trend last month, with a 17.7 per cent year-on-year increase.
Electrified vehicles such as pure electrics, plug-in hybrids and hybrids accounted for three out of ten new cars in May.
SMMT chief executive Mike Hawes said: “In yet another challenging month for the new car market, the industry continues to battle ongoing global parts shortages, with growing battery electric vehicle uptake one of the few bright spots.
“To continue this momentum and drive a robust mass market for these vehicles, we need to ensure every buyer has the confidence to go electric. This requires an acceleration in the rollout of accessible charging infrastructure to match the increasing number of plug-in vehicles, as well as incentives for the purchase of new, cleaner and greener cars.
“Delivering on net zero means renewing the vehicles on our roads at pace, but with rising inflation and a squeeze on household incomes this will be increasingly difficult, unless businesses and private buyers have the confidence and encouragement to do so.”
Ian Plummer, commercial director at Auto Trader, said: “Today’s weak new car figures underline the lingering challenges for carmakers, as the war in Ukraine adds to the headwinds of a post-Covid shortage of semiconductors and lockdowns in China.
“Even though the microchip shortage is easing a little, manufacturers are struggling to source critical components like wiring looms, which are a major Ukrainian export and hard to replace.
“While there are some signs of dented consumer confidence now dampening car buying demand from its recent highs, the main issue in the new car market lies with supply rather than demand with most brands and dealerships boasting bulging order books and buyers typically waiting many months for deliveries.”
Karen Johnson, head of retail and wholesale at Barclays Corporate Banking, said: “This month brings no surprises, with car sales down and supply issues showing no signs of abating.
“Electric is the only area that offers dealers something to smile about, with sales across this category holding firm. The changing balance between electric and traditional vehicle sales will be key to the future of car dealers, consumers and the economy in general.”
Alex Buttle, co-founder of used car marketplace Motorway.co.uk, added: “Like a lighthouse in a storm, new EV sales provide a beacon of hope to the car market that things aren’t all doom and gloom as they once again buck the trend for new car sales.”