The largest donor to the United Nations Environment Programme (Unep) has paused funding to the body before its revised budget on 12 May, triggering concern among member states and NGOs.

The news could carry significance for the already troubled plastic treaty negotiations being overseen by Unep. Since 2022 countries have been struggling to agree on how to deal with the volume of plastics being produced and used, a subject widely acknowledged to be one of the most serious environmental issues of the age, but despite six rounds of talks there has been no agreement in sight.

Unep’s executive director, Inger Andersen, met the director general of the Norwegian Agency for Development Cooperation (Norad) the week before last and was told that “all [funding] agreements are on hold” pending budget decisions, according to sources.

Norway has been the largest overall donor to Unep in recent years, contributing approximately $12m(£9m) annually over the past three years to the fund (to 2025). Norway also contributed $19m in 2025 to the Planetary Fund and another $7.8m in earmarked funds in 2025, meaning that even a pause introduces significant uncertainty for future functioning of the global environment agency with the wider UN already facing severe financial pressure.

In addition, the Guardian has obtained an email sent to NGOs by Norad advising them that it was postponing a funding call aimed at projects to combat plastic pollution in developing countries.

The programme is valued at £4m-£6m a year and, according to Norad, the funding can be used for projects that support countries in the plastic treaty process. Christina Dixon, ocean campaign leader at the Environmental Investigation Agency, said: “Any risk to funding could not come at a worse time for the negotiations … sustained funding would reinforce Norway’s longstanding leadership toward an ambitious plastics treaty.”

Norway is the co-leader with Rwanda of the high ambition coalition at the plastic treaty negotiations. The coalition says it is working for an “ambitious” and legally binding instrument on the “full life cycle of plastics”. This stands in contrast to a small group of petrostates, who are widely seen as blocking moves to put a cap on plastic production.

Last year, the chair of the process resigned suddenly, with the talks in disarray. This came just months after the previous round of talks collapsed with little progress and three years of negotiations. A new chair was elected this year, with negotiations expected to resume in early 2027.

Karen Landmark, managing director at GRID-Arendal, a Norwegian environmental foundation that works closely with Unep, said her organisation was concerned the funding pause could “give other countries an excuse to lower their level of ambition”.

“For years, Norway has played a clear and constructive leadership role in pushing for a strong global plastics treaty. When a country in that position signals hesitation or withdraws support, the consequences can extend far beyond its own borders,” she said.

Oil and gas is Norway’s largest sector with petroleum revenues amounting to £52m in 2025 alone, and last week the government was criticised for approving plans to reopen three of its North Sea gasfields to help fill the gap in energy supplies created by the Middle East war.

Frøya Skjold Sjursæther of the Green party said: “It’s a complete scandal if Norway moves to cut support for the global plastic clean-up effort. Norway has long worked for a global plastics treaty, and rightly so, given that Norwegian oil contributes to millions of tonnes of plastic every year.”

Norway’s reassessment of Unep funding comes amid a shifting domestic political and economic debate over climate and environmental spending. The country is governed by the centre-left Labour party, which has continued to position Norway internationally as a supporter of climate diplomacy, rainforest protection and efforts to negotiate a global plastics treaty. However, the Jonas Gahr Støre-led government, which was elected last year, is a minority administration and relies on agreements with other parties to pass budget measures.

When asked about the postponement of the plastics funding communicated to NGOs, Per Fredrik Pharo, head of Norad’s department for climate and nature, said there were several agreements for funding; that the main one was due to finish last year and had done so while another was “in an assessment process … where we need to determine the scale and scope of future cooperation”. That process will be finished mid 2026.

Another stream has been postponed but this work will be resumed “in the near future”. This adds to NGO confusion after a Norad minister recently noted in the Norwegian parliament that Norway would continue its funding to combat plastic pollution in developing countries, with an “ambition” to spend 1bn kroner (£79m) between 2025 and 2028.

Eirik Lindebjerg, conservation director of WWF Norway, issaid he was concerned by the “vague” language, adding: “If they are planning to continue with this, then why create so much uncertainty?”

Åsmund Aukrust, Norway’s minister of international development, said the Labour party governs in an “unpredictable economic situation” and that “every krone in the budget must be carefully considered”.

A Unep spokesperson said: “We have every faith that Norway will continue their strong environmental leadership.”