The European Union is set Thursday to propose emissions rules for the continent’s last generation of combustion engines, according to a document obtained by Bloomberg News.

The trading bloc is expected to announce regulations governing the so-called Euro 7 engines, powering the final wave of petrol and diesel cars that’ll hit the market before they’re effectively banned by new emissions rules in 2035. The new framework will tighten restrictions for pollutants including carbon monoxide and nitrogen oxides from 2025.

Adoption of the rules has been delayed several times amid wrangling over their contents. Automotive executives including Carlos Tavares, chief executive officer of Stellantis NV, have argued the latest steps in cutting CO2 from cars pose unnecessary burdens on the industry and will slow the sector’s shift to electrification.

Supporters of the rules argue that some vehicles going on sale between 2025 and 2035 will be sold in the second-hand market and run on the roads for decades, meaning more stringent rules on particulate pollution could end up saving thousands of lives.

“Transition towards zero-emission cars/vans fleet will be spread across at least two decades, not least given the average lifetime of cars/vans of more than 11 years,” the draft said. “Meanwhile, in order to achieve the above policy objectives, the internal combustion-engine vehicles which will continue to be placed on the market need to be as clean as possible.”

The rules, part of the European Green Deal aimed at putting the continent’s economy on a sustainable footing, will develop stricter emissions standards for all petrol and diesel cars, vans, lorries and buses.

A decision on Euro 7 would come after the bloc last month reached a landmark deal to effectively ban new combustion-engine cars from 2035, forcing companies to overhaul their lineups. The push poses risks to employment and vehicle affordability, EU Internal Market Commissioner Thierry Breton said last week, hinting a delay in the policy may be possible in 2026.