Washington: The US Supreme Court on Tuesday put on hold President Barack Obama’s sweeping plan to reduce greenhouse gas emissions from coal-fuelled power plants pending a legal challenge.

A coalition of 27 US states is suing in a lower court to halt Obama’s Clean Power Plan, and petitioned the Supreme Court to suspend its implementation until the case is resolved.

Most of the states involved are run by Obama’s Republican adversaries.

Tuesday’s ruling, backed by five of the nine Supreme Court justices, deals a significant blow to Obama’s efforts to rein in man-made climate change.

The court’s four liberal voices contested the decision to halt the emission rules, which would require the power sector’s carbon dioxide emissions to be slashed by at least 32 per cent compared to 2005 levels by the year 2030.

The far-reaching regulations issued last summer by the Environmental Protection Agency form a core of Obama’s efforts to reduce overall US greenhouse gas emissions.

But many US conservatives deny that climate change is caused by human industry and agriculture, and have opposed emissions controls designed to slow global warming.

The federal program was a central part of the commitments put forward by Washington ahead of the Paris climate deal struck by 195 governments in December.

Democratic White House hopeful Bernie Sanders voiced bitter disappointment, as voting wrapped up in the New Hampshire presidential primary.

‘The Supreme Court’s decision is deeply disappointing. There’s no time to spare in the fight to combat climate change,’ he tweeted.

But the attorney general for West Virginia, Patrick Morrissey, hailed it as a major victory against efforts to regulate the coal industry.

‘Hope. Coal miners and their families should have more hope tonight after our unprecedented victory at the US Supreme Ct. We stayed the CPP!’ tweeted Morrissey, whose state leads the group opposing the Obama plan.

The EPA rules have incensed Republicans, particularly lawmakers from coal-producing states.

They argue that the economic cost of the endeavour would cripple industry and hike energy costs for millions of Americans.

Republicans in Congress late last year voted through two so-called disapproval resolutions on the emissions rules, dealing a largely symbolic yet blunt rebuke to Obama.