The UK new LCV market plunged by 23.5% year-on-year in September, according to the Society of Motor Manufacturers and Traders (SMMT).

The organisation has blamed the decline on regulatory changes – the WLTP vehicle testing regime, which wreaked havoc in the new car market 12 months previously, came in for LCVs in September – along with political and economic uncertainty.

On a sector-by-sector basis, the bestselling 2.5t-3.5t van segment saw registrations fall by 35.2%, to 22,338, while pick-up trucks were down by 18.8% to 7,814 registrations, and the niche 4×4 segment down by 48.4% to 163 registrations.

However, in a very uneven marketplace these falls were far from uniform, with the 2.0t-2.5t segment recording a 16.8% increase to 7,975, while registrations of vans weighing less than 2.0t rose by 12.3%, to 2,926.

September is the first month of 2019 in which year-on-year sales have fallen, and the LCV market for the year to date now stands up by 4.5% compared with 2018, with 286,616 vehicles registered.

SMMT chief executive Mike Hawes said: “These figures are unusual as LCV registrations have been growing this year, but the impact of regulatory changes, coupled with ongoing political and economic uncertainty, distorted the market in September.

“Registrations for the year-to-date are still healthy, however, but for this to be maintained we need stability restored, which should give renewed confidence to businesses to invest in their fleets.”

Regular market leader the Ford Transit Custom regained its place at the number one spot in September, with 5,653 examples registered.

The Vauxhall Vivaro was second, with 2,827 registrations, and the top five was completed by the Ford Ranger (2,377), the Peugeot Partner (2,350), and the Ford Transit Connect (2,304).

Significantly, the Mercedes-Benz Sprinter, which was the UK’s bestselling LCV in August, fell to sixth place, with 2,095 registrations, while the Ford Transit, the UK’s second-bestselling van for the year to date, was down in ninth place with 1,939 examples registered.

It was also a below-par month for the Volkswagen Transporter, the UK’s fourth-bestselling van in 2019, which was down in 10th place, with 1,744 examples registered.