Labour was last night urged to ignore pressure from eco-zealots and to push ahead with drilling in Britain’s largest untapped oil field.

Energy Secretary Miatta Fahnbulleh was poised to reject plans to exploit the Rosebank site – just hours after approving production at the Jackdaw gas field.

Calls from union bosses and Labour MPs to press ahead with oil extraction were backed by Donald Trump who urged the UK to go ‘full blast’ and exploit the North Sea’s resources.

But Ms Fahnbulleh signalled that she is likely to reject the plans, saying she did not apply the same rationale to each of the projects.

Climate campaigners object to Rosebank because it would emit about seven times the carbon dioxide of the Jackdaw site.

Ed Miliband, the Foreign Secretary and former energy secretary, is said to be staunchly opposed to the new drilling. Ms Fahnbulleh said: ‘One is a gasfield that caters for the domestic market, while the other is an oilfield that is mainly for export.

‘It is right that we judge each application in its own right, and it is absolutely critical that the decision is consistent with our climate obligations, our carbon budgets and the end destination we need to get to with the energy transition.’

She has already faced objections from Left-wing Labour MPs to her decision to grant permission for Jackdaw, which could begin supplying gas to British homes and businesses within weeks.

The field could account for 6 per cent of North Sea gas production when fully operational and provide a £2.9billion economic boost while protecting jobs.

But Ms Fahnbulleh conceded that it would not mean cheaper energy bills, saying that it would instead contribute to energy security at a time of war in the Middle East.

Unions welcomed her decision to back Jackdaw, with Gary Smith, the GMB general secretary, saying the Government deserved ‘real credit’ for it.

But he urged ministers to go further and approve Rosebank too – a decision that is likely to prove more controversial.

Rosebank is a far bigger project believed to contain between 300million and 500million barrels of oil which could make up about 8 per cent of UK oil production.

The emissions eventually produced by the oil would be seven times those produced by the gas from Jackdaw, say campaigners.

Scottish Labour leader Michael Marra has previously told Andy Burnham that he supports drilling in Rosebank and has argued that it would boost Scotland’s economy.

The Unite general secretary Sharon Graham welcomed the decision on Jackdaw and has previously urged the Government to support Rosebank.

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