The European Commission will propose tough regulations on chemicals this week, rejecting misgivings from one of the EU's biggest industries, EU Environment Commissioner Ms Margot Wallström said yesterday.

The Commission's plan has sparked a lobbying war between environmentalists, who want a crackdown on toxic substances, and the EU's €528 billion per year chemical industry, which says the new rules could spell its ruin.

The Tánaiste, Ms Harney, has lobbied strongly against the proposals, which she fears could cost thousands of jobs in Ireland. The chemicals industry has also urged delays to perform an economic impact study. But Ms Wallström, the driving force behind the plan, said yesterday there would be no delay.

"It will be discussed and decided on Wednesday in the Commission," she said in an interview. "We have made an impact assessment and we are adding that to our proposal."

The Bill aims to identify toxic threats to humans and the environment that may lurk in everyday chemicals by forcing firms to register the qualities of thousands of substances they make in a central EU database so they can be screened for safety.

The most problematic substances - for example ones that cause cancer or affect fertility - could be banned, or makers and users could need a special authorisation to use them.

A spokesman for the EU executive said last week that divisions within the Commission might delay the Bill, which senior Commission officials were still finalising at a meeting in Brussels yesterday. An official said there could be some changes to a draft, which has already been heavily modified in favour of industry.