The United Kingdom will issue a “call to action” this week with a group of European nations to attack the so-called “shadow fleet” of oil tankers that Russia is using to evade international sanctions, Bloomberg reported Monday.

An unspecified number of countries are expected to endorse the plan on the sidelines of a meeting of the European Political Community (EPC), organised by Great Britain on Thursday by Prime Minister Keir Starmer: The aim is to share information on the Russian fleet “in order to coordinate our responses to the risks posed by their vessels and facilitators, and to work with the private sector and other maritime stakeholders to address the threat.

European nations are trying to make it harder for Russia to profit from its oil resources. The G7 sanctions have sought to turn Russia into a pariah in traditional oil transportation markets by cutting off access to major oil tankers and service providers unless the oil being transported is below a G7 price threshold. This has forced Moscow to turn to legacy carriers that operate outside industry standards.

“Russia’s shadow fleet poses a threat to our countries and other countries that depend on the world’s seas and oceans,” the document, which could be signed this weekend, says. “Many of the ships in this ‘shadow fleet’ are uninsured and poorly maintained. Many of them are engaged in activities that violate basic safety and environmental standards and regulations.

Until June, most sanctions were for price cap violations, giving Russia an even greater incentive to avoid using Western services altogether. It has also fueled a boom in the use of older tankers — often with uncertain insurance status and murky ownership — that form a “parallel fleet.” Some oil workers falsify their location to try to hide their activities.

Last December, the International Maritime Organization approved a resolution urging all member states and interested parties to strengthen measures “to prevent illegal maritime operations by the ‘black fleet’ or ‘shadow fleet.’” The European Union cited the resolution when it imposed sanctions on several Russian oil tankers last month, and the UK has already begun directly targeting “shadow fleet” vessels.

There are signs that these sanctions have been effective, at least in terms of disrupting tankers carrying Russian oil. Of the roughly 50 ships sanctioned since late last year by the United States, the United Kingdom and Europe, the vast majority have been unable to load their cargoes later.

At the EPC meeting, European countries will also call for the implementation of safety rules, including those relating to ship-to-ship transfers and requirements for valid insurance certificates on board, according to the statement. “We urge shipowners and operators, the marine insurance industry, ship brokers and other relevant maritime stakeholders to comply with their relevant obligations and support the prevention, detection and reporting of ‘parallel fleet’ activities,” it said.