In a plenary session the European Parliament has voted to impose tougher rules governing the environmental impact of oil and conventional gas exploration, while at the same time exempting shale gas.

The vote of followed a compromise on the draft law in December, struck only after negotiators agreed to leave out references to shale gas. Industrial interests had urged that too many restrictions not be placed on projects in the early phase when commercial viability is unclear.

EU member states are expected endorse the legislation in the coming weeks, after which the law will become final.

Under the proposed rules, assessments of a range of infrastructure projects, as well as oil and gas, will include their impact on biodiversity and climate change, in addition to measures to ensuring that authorities granting approval have no conflict of interest.

Roland Festor, director for EU affairs at the International Association of Oil & Gas Producers, said, however, that the new rules "will guarantee that any development, including exploration for shale gas, will be subject to strict environmental standards."

Shale Gas Europe, which brings together exploration companies led by Chevron, Total and Cuadrilla Resources, also welcomed the law. "Shale gas could potentially play an important role in meeting Europe's acute energy challenges," Marcus Pepperell, spokesman for the industry grouping said.

Green politicians called the decision to exempt shale gas a major setback adding that the fracking process, which involves using chemicals to extract gas from the shale rock, poses risks to health and the environment.

Sandrine Belier, environment spokeswoman for the European Green party, said "the Greens believe there is already sufficient evidence to ban fracking, but ensuring informed permit decisions through the environmental impact assessment procedure must be the absolute minimum."