WASHINGTON (Reuters) - U.S. Democratic presidential contender Bernie Sanders will roll out a series of environmental proposals to coincide with this month’s United Nations climate-change conference in Paris that could also put pressure on party front-runner Hillary Clinton.

With a United States flag draped behind him, U.S. Democratic presidential candidate and U.S. Senator Bernie Sanders speaks during a campaign town hall meeting at Pinkerton Academy in Derry, New Hampshire October 30, 2015. REUTERS/Mary Schwalm

Sanders, a U.S. senator from Vermont, on Wednesday at a U.S. Capitol rally, backed a proposal to halt new leases for fossil fuel extraction on public lands alongside the bill’s sponsor, fellow Democratic U.S. Senator Jeff Merkley of Oregon.

Sanders said he would soon unveil legislation that would protect fossil fuel industry workers as the country transitions to renewable fuel sources. Aides told Reuters that would be the senator’s next step in presenting a comprehensive climate plan.

“We are not going to let them fall by the wayside,” Sanders said of workers at the Wednesday event.

Leaders from nearly 190 countries are set to meet in Paris at the end of November to reach an agreement on curbing human-caused climate change.

Sanders, who calls himself a democratic socialist, is Clinton’s main rival for the party’s presidential nomination for the November 2016 election. His stances on the environment, trade and more have pressured Clinton to move to the left.

Still, polls have shown that Clinton, the former U.S. secretary of state, has gained ground over Sanders recently.

But Clinton’s pragmatic approach to climate change has frustrated some environmental activists who seek to pressure her into taking tougher stances.

Merkley acknowledged his Sanders-backed bill to halt leases to extract fossil fuels on public lands, and in the Pacific and Gulf of Mexico, will face fierce opposition in the Republican-controlled U.S. Congress, where it is unlikely to become law.

But it should help Sanders appeal to environmental activists and could pressure Clinton, who said in July that it would be irresponsible to abruptly halt oil, natural gas and coal extraction on federal lands. Clinton instead called for a gradual phase out on public-land extraction and increased fees.

“We still have to run our economy, we still have to turn on the lights,” Clinton said.

Sanders is likely to introduce bills related to carbon pricing and a tax incentives package for renewable fuels, aides said. His campaign is likewise poised to present its full climate-change platform ahead of the Paris talks, which the senator may attend, his campaign confirmed.

“This is a major, major, major, planetary crisis,” Sanders said Wednesday, referring to climate change.

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