But in a summary of an internal meeting published on its website, it noted the difficulty of meeting targets set in 2013 aimed at assuaging public anger over damage to the environment after three decades of breakneck growth, with many areas still not up to scratch.

“The completion of the targets and tasks of the (2013) 10-point air quality action plan is still facing huge pressure,” the ministry said, citing environment minister Li Ganjie.

At the start of this year, emissions of small hazardous particles known as PM2.5 hit near-record highs in Beijing and surrounding Hebei province, prompting the region to take emergency measures to thin traffic and curb industrial activity.

Liu Bingjiang, head of the ministry’s air quality department, said on Friday that China would take even sterner action this year ahead of the winter spike in coal usage.

“This is the first time we have made a detailed plan for autumn and winter and our targets are twice as high as last year,” he said, noting that as many as 44,000 coal-fired boilers would be shut down.

The government has expressed confidence that air quality would improve compared to last year, but emissions in the smog-prone Beijing-Tianjin-Hebei region have risen in the first seven months of 2017.

The ministry aims to reduce emissions of PM2.5 by at least 15 per cent in the coming months, while the capital Beijing will be forced to reduce PM2.5 readings by more than 25 per cent year on year over winter months to meet its targets.

Wary of the impact the crackdown will have on commodities markets, the ministry has warned local governments not to use a “one size fits all” approach to implementing environmental policies, but some prices have already surged.

Hebei is home to a quarter of national steel production and its cities will be forced to cut output by as much as 50 per cent over winter in a bid to reduce smog. Production of aluminium, glass and cement is also expected to take a big hit.