The UK's Royal Automobile Club has warned that drivers may face fines for leaving their vehicle engines idling with the air conditioning on while stationary. Under current regulations, police officers can issue an on-the-spot fine of £40 if they observe this behavior, while civil enforcement officers can impose a penalty of £80. Some local authorities have higher penalties; for example, in the London borough of Islington, drivers who refuse to comply with an enforcement officer’s instruction to switch off an idling engine can be fined £110. This practice has drawn enforcement attention due to its contribution to air pollution. Although the UK government had planned in 2019 to increase these fines, the proposal was ultimately not implemented.