The window to stop the decline of England’s nature is swiftly closing, the environmental watchdog has said, as its latest report finds that the government is falling short on most of its targets to improve the environment.

Some of Labour’s actions, however, including setting up a water commission and writing a new environmental improvement plan, were praised by the Office for Environmental Protection (OEP) in its annual review of how the government was meeting the legally binding environment targets.

The OEP’s chair, Glenys Stacey, said: “With each passing month, the window of opportunity to redress environmental harms is closing, while the effort needed and cost to do so increases. This government must act urgently and decisively to catch up if it is to meet its legal obligations.

“Catch up not just by developing plans, but then by fully and effectively implementing them. It has several legally binding commitments only a few years away. The window of opportunity is closing fast.”

The OEP was set up after Brexit. It holds the government to account under the Environment Act 2021, which was passed to replace EU law. The EU can sanction member states if they fall behind on environmental standards, but once the UK had left, this was the only way to hold ministers to account.

The OEP’s assessment of the government’s prospects of meeting 43 environmental targets and commitments found that it was largely on track to achieve nine, partially on track to achieve 12 and largely off track to achieve 20. Partially on track means the government will fail to hit the target but has made progress. Two targets could not be assessed on account of insufficient evidence. Last year the government was largely on track to achieve four, partially on track to achieve 11 and largely off track to achieve 10.

Improvements are mostly being made in terms of pollution. Some air pollutants such as PM2.5 are falling, and positive action is being taken on some water pollutants such as phosphorus. There are also signs that the downward trend in species abundance is slowing.

Areas of concern include the marine environment, achieving “thriving plants and wildlife”, and general biodiversity trends. According to the OEP’s chief scientist, Robbie McDonald, the oceans around England were likely to miss their target of being in good ecological status by 2027 as a result of pressures including overfishing and pollution.

The previous government set up marine protected areas (MPAs) but damaging actions such as bottom trawling have not been stopped in them. “We should already have been taking action to stop damaging actions in MPAs,” McDonald said. “This needs to happen now.”

The report also stresses the importance of properly funding and regulating England’s protected areas for nature, such as sites of special scientific interest and national landscapes. Funding for the protection of these areas is likely to be cut, however, in the upcoming spending review.

Nature-friendly farming schemes need to be boosted if nature is to be healed, the report also said. “There are not an awful lot of quick wins but we will always turn to the importance of how we can get nature-friendly farming right,” McDonald said. “Anything the government can do to put the wind in the sails of building networks of farmers to drive nature recovery at scale, we would say that should be prioritised.”

Farmers are almost the sole driver of increased tree planting, the report noted, because England’s tree action plan, which supported the expansion of woodland, ended last year. It said that while farming schemes “are foreseen as the primary vehicle for tree planting, the government cannot rely solely on these”.

A spokesperson for the Department for Environment, Food and Rural Affairs said: “After years of failure, nature across Britain is suffering. The report is absolutely right to point out that the window to fix it is closing.

“This is why the government is taking urgent action to put nature on the road to recovery which has been welcomed by the OEP.”