FirstGroup plc t/a FirstBus (FirstGroup) said they believed the complainant had misinterpreted the ads, because they did not refer to low emission buses specifically but to low emissions. They said that regardless of the interpretation they did not believe that the DfT's definition of low emission buses was widely known among the general public.

FirstGroup said the claim referred to their corporate aims and their commitment to making demonstrable improvements to emissions through a range of initiatives, including new vehicle technology and driver training and monitoring. They said that as a result of those initiatives, they had lowered CO2 per passenger by 8% and their target for the next four years was to reduce emissions by a further 10%.

Clearcast responded to the complaint about ad (a) only. They said they had ensured the "We love low emissions" claim was qualified with on-screen text stating how much less CO2 FirstGroup buses produced compared to conventional buses. They said that because the qualifying text appeared on-screen at the same time as the claim, no one would have been misled by the "low emissions" claim.

Clearcast said their motoring consultant had reviewed and approved the 4.97% figure. He had advised that the DfT considered buses that produce 30% less carbon to be low emission buses because 30% was used as a guideline to measure the DfT's carbon credits scheme, which was driven by government emission targets. They said the DfT's definition of a low carbon emission bus was for the Department's own internal purposes, and was irrelevant to the claim in the ad.