The business secretary Sajid Javid has said he will back staying in the EU because the state of global markets would make an exit too much of a risk to the UK economy.
He will join David Cameron in campaigning for the UK to stay in the EU after the Prime Minister finally sealed a deal for new terms of membership.
Javid said it was with "a heavy heart and no enthusiasm" that he would vote for remaining part of Europe. "My heart says we are better off out. My head says it’s too risky right now," he said, writing in the Mail on Sunday.
He revealed that he came close to falling into the Leave camp, but after weighing the short term costs of an exit on economic growth against the long term gains, he fell on the Remain side, citing the clouds of the turbulent global economy.
"But, in recent months, we have once again seen storm clouds gathering over the global economy. As a former financial analyst, I still take a keen interest in the markets. Far more important than what the commentators are saying is what the markets are forecasting: a significant global economic downturn," said Javid.
"The fallout from a Leave vote this summer would only add to economic turbulence that is, quite possibly, about to engulf the world."
Javid has said before he is not afraid of voting Leave, however, the difficulty of getting consent from the 27 remaining states for new trade agreement terms "simply cannot be achieved overnight" he said.
"These complex agreements have been built up over the course of nearly half a century, and nobody can say how many years will pass while they are unpicked and rewoven for a post-Brexit Britain. I worked in international business long enough to know that uncertainty is the single biggest enemy of growth."
The backing is a boost for Cameron and the "In" campaign, however, the reforms brokered in the negotiations are not enough, he argues, and that there is room for further negotiation.
"I am disappointed by the scope and scale of the reforms offered by the European Council. However, thanks to the Prime Minister, it is definitely a step in the right direction – and, crucially, one that shows reform is possible."
Javid also raised the prospect of a second referendum in more favourable economic conditions in the future.
"For me, this referendum does not have to be a once-in-a-generation event. The fight for reform is not over and if Brussels fails to recognise that, I can see a time when walking away may be the right thing to do – but in a more benign global economic environment and under a UK Government that makes a credible case for leaving."