Green group Transport & Environment (T&E) is claiming some shipowners will slip through the net of the European Union's emissions trading scheme (ETS) due to loopholes.

The group blamed "arbitrary exemptions" for some vessel classes, meaning that millions of tonnes of CO2 will not be covered by the carbon-pricing scheme from 2023.

T&E said this undermines the integrity of the EU's shipping laws.

The group calculates that more than 25.8m