The government is to allow longer lorries on UK roads to reduce the number of journeys - despite fears the move will cost lives.

The Department for Transport (DfT) announced lorry trailers up to 61ft (18.55m) long - some 6ft 9in (2.05m) longer than the standard size - will be permitted from 31 May under legislation going before Parliament on Wednesday.

But it is feared the changes will create greater dangers for pedestrians and cyclists, and the potential for damage to roadside infrastructure.

Vehicles covered by the new laws have a larger tail swing - meaning their rear end covers a greater area when turning - and extended blind spots.

Campaign groups say the decision is "alarming" and claim most of the testing during the 11-year trial of longer lorries took place on motorways and A-roads.

They say pedestrians and cyclists on roads in town centres and rural areas are now most likely to be put at increased risk.

Keir Gallagher, campaigns manager at Cycling UK, told Sky News: "At a time when funding for infrastructure to keep people cycling and walking safer has been cut, it's alarming that longer and more hazardous lorries could now be allowed to share the road with people cycling and walking.

"Before opening the floodgates to longer lorries rolling into our busy town centres and narrow rural lanes, further testing in real-life scenarios should have been done to assess and address the risks."

The campaigner added: "Counting casualties years down the line is the wrong way to conduct road safety policy - yet just like with smart motorways, that's the risk we face."

Lobby group Campaign for Better Transport called on the government to rethink its plan - and focus on ensuring more freight is moved by rail - "an efficient, safe and clean alternative, with just one freight train capable of removing up to 129 lorries from our roads".

Cycling UK said calculations based on official figures found HGVs accounted for 3.4% of traffic - but were involved in 15.5% of cyclist and 11% of pedestrian deaths.

The DfT said the new lorries would be able to move the same volume of goods as current trailers in 8% fewer journeys, meaning they will "make the world of difference" for businesses such as bakery chain Greggs.

It claimed the policy could generate £1.4bn in economic benefits and take one standard-size trailer off the road for every 12 trips.

The department insisted its 11-year trial showed the longer lorries were safe for use on public roads - and found they were involved in "around 61% fewer personal injury collisions than conventional lorries".

A government-commissioned report published in July 2021 revealed that 58 people were injured in incidents involving longer lorries between 2012 and 2020.

Roads minister Richard Holden said: "A strong, resilient supply chain is key to the government's efforts to grow the economy."

Longer lorries will be subject to the same 44-tonne weight limit as those using standard trailers.