Jim O'Neill
Economist O'Neil coined the terms BRICs (Brazil, Russia, India and China) in 2001Reuters

The top Conservative behind George Osborne's so called Northern Powerhouse project has quit the government today (23 September).

Lord Jim O'Neill's resignation as commercial secretary to the Treasury is the first of Theresa May's administration. O'Neill, a former Goldman Sachs economist, is also resigning the Tory whip to become a cross-bench peer.

O'Neill played a central role in Osborne's plan to devolve more powers and control to the North of England in a bid to boost the region's economy.

He also chaired the Cities Growth Commission in the UK until October 2014, when it provided its final recommendations.

May said she was "absolutely committed" to the Northern Powerhouse project, but O'Neill threatened to quit the government in August if the new Conservative premier downgraded the previous administration's plans.

O'Neil, who coined the terms Bric (Brazil, Russia, India and China) in 2001, mentioned the government's policy over China and India in his resignation letter to May.

"The case for both to be at the heart of British economic policy is even stronger following the referendum, and I am pleased that, despite speculation to the contrary, both appear to be commanding your personal attention," he said.

"I am leaving knowing that I can play some role supporting these critical initiatives as a non-governmental person." O'Neil also said he was looking forward to "moving to the cross benches of the Lords". It has been reported that O'Neil disagreed with May's stance on the Hinkley Point C deal behind the scenes.

Elsewhere, he led a government review into the global challenge of antimicrobial resistance.

"Leading this review has been one of the most stimulating roles I have ever undertaken and I am very grateful to all those involved, especially my review team, and all those across government that allowed the UK to take such a global leadership position in this key threat to the world," O'Neil said.

"It goes without saying that our success is symbolic of the way that the UK can be influential in a post-Brexit world."