The UK has said publicly for the first time that it will back a moratorium on deep-sea mining, after its previously supportive stance for the controversial practice came under fire from scientists and parliamentarians. The government on Monday announced its support for a temporary suspension of sponsoring or supporting licences for projects to exploit metals from the seabed until enough scientific evidence was available to assess its impact.

The move brings the UK in line with Brazil, France and Germany, which are among more than 20 countries to have called for a pause in deep-sea mining, at least until the environmental effects are better understood. A new UK-based network of experts will be set up to gather more scientific data and deepen understanding of the impact, said the Department for Environment, Food and Rural Affairs. The UK will use its “scientific expertise to fully understand the impact of deep-sea mining on precious ecosystems and in the meantime, we will not support or sponsor any exploitation licences”, said environment minister Thérèse Coffey.

Rishi Sunak’s government has been criticised by the opposition Labour party, scientists and a cross-party group of parliamentarians as a laggard for its continued support for extracting minerals from the seabed, which it has called “precautionary and conditional”. The International Seabed Authority, which regulates deep-sea mining in international waters, met in July but no decision was reached on whether to allow production to go ahead. However, its 168 members agreeed to discuss a moratorium at next year’s negotiations.

In March and July, UK delegates to the ISA said their government would not sponsor or support deep-sea mining exploitation licences without the relevant scientific evidence but Monday’s announcement marks the first public declaration of the position. Activists argue that a moratorium is necessary to avoid irreversible damage that may be caused to ancient ecosystems by the practice. Duncan Currie, a lawyer at the Deep Sea Conservation Coalition, an NGO, said that “it’s encouraging to see the UK has now strengthened their position and are saying no to deep-sea mining”.

Advocates say that digging up the seabed for metals would avoid the environmental damage of land-based mining and help the west to reduce its reliance on China for critical minerals. Despite the moratorium on deep-sea mining, exploration can still go ahead. The British government has sponsored two exploration licences to extract key battery metals from nodules that sit on the bottom of the Pacific Ocean, which are held by Loke, a Norwegian company. Walter Sognnes, chief executive of Loke, said that “this is fully aligned with our precautionary principle, we see the need to close the knowledge gap and we will not be ready to apply for exploitation licences until there are strict regulations in place”.