Some of the country’s largest law firms do not pay any carbon tax, while smaller competitors are facing bills of £50,000 a year or more, according to new research.

City firm Herbert Smith (pictured right), with 700 lawyers in London, pays no carbon tax, compared with almost £50,000 paid by City firm Lawrence Graham with 415 lawyers. City firms Simmons & Simmons (400 lawyers) and Ashurst (500 lawyers) also pay no carbon tax.

The anomaly is revealed in a report by the Environmental Data Services (ENDS) into the operation of the carbon reduction commitment energy efficiency scheme. The scheme, run by the Department of Energy and Climate Change, is mandatory for all heavy consumers of energy, requiring them to buy carbon emission allowances - in effect, a carbon tax - based on their past year’s performance.

The ENDS report stressed: ‘None of our learned friends is doing anything wrong.’ The large City firms pinpointed by the research do not feature in the carbon reduction scheme because they are tenants of office buildings where landlords pay the energy bills.