For products submitted to energy labelling obligations, it is not allowed to 'provide or display other labels, marks, symbols or inscriptions', if doing so would be likely to mislead or confuse customers regarding energy consumption of that product [...].Displaying any third country regulated energy label, such as the one applicable to products to be placed on the GB market could be pursued by market surveillance authorities as a violation of the EU anti-mimicking prohibition for products under their jurisdiction.
For products not covered by energy labelling requirements and even for non-energy-related product suppliers and dealers are strictly prohibited from supplying or displaying any labels that mimic the official EU energy labels. This prevents companies from creating deceptive, look-alike energy scales (such as unauthorized green-to-red color scale or A–G classification scales) on unregulated goods to falsely imply an official EU environmental rating that undermines the energy labelling reputation.
Disclaimer: Please note that the European Commission cannot provide a legally binding interpretation of the EU legislation, as this is the sole competence of the European Court of Justice. Any remarks from the European Commission services are without prejudice to the position the Commission might take should related cases arise in a procedure before the Court of Justice.