Britain's advertising watchdog on June 7 banned some advertising by energy giant Shell on posters, television and on YouTube, saying it gave a misleading impression of the size of the group's lower carbon business.

The ruling adds pressure on globally active energy companies with substantial fossil fuel businesses that also want to advertise their renewable power and lower-carbon products.

The Advertising Standards Authority (ASA) said on its website it scrutinized advertisements that featured details of Shell's renewable power business, electric vehicle charging and the slogan: "The UK is READY for cleaner energy," followed by the Shell logo.

Around two thirds of Shell's global $25 billion budget last year went towards oil and gas, while the company invested $4.3 billion in renewables, biofuels, hydrogen and electric vehicle charging.

Shell UK has said it aimed to invest up to 25 billion pounds ($31 billion) in the British energy system over the next decade, of which more than 75% is intended for low and zero-carbon technology.

"(The) Ads... must not appear again in the form complained of," ASA said, referring to a challenge by the campaign group Adfree Cities.

"We told Shell UK Ltd to ensure that their future ads featuring environmental claims did not mislead by exaggerating or, omitting material information about, the proportion of their business activities that were comprised of lower carbon activities."

A Shell spokesperson said: "We strongly disagree with the ASA’s decision, which could slow the UK’s drive towards renewable energy. People are already well aware that Shell produces the oil and gas they depend on today."

The spokesperson added that the transition away from fossil fuels needed people to be aware of "the alternatives available to them".

Shell has a target to become a net zero carbon company by 2050.

ASA on June 7 also ruled against advertisements by Spanish energy firm Repsol about its renewable fuels and Malaysia's Petronas' net zero plans.