The Transatlantic Trade and Investment Partnership (TTIP) has spooked a fair few people with its potential for "irreversible" privatisation and unprecedented power for corporations. Jeremy Corbyn says he's one of them.
After setting out the "positive" case for Remain, Corbyn said Labour would push for reforms in the European Union, including to strengthen workers' rights, deal with the migration crisis and "democratise" institutions in Brussels.
The Labour leader then shared his thoughts on TTIP, vowing to scrap the deal if Labour win power. Here's what he said in full:
"Thousands of people have written to me with concerns, deep concerns, about TTIP - the deal being negotiated, largely in secret, between US & EU officials.
"Many are concerned, quite rightly, that it could open public services to further privatisation and make privatisation effectively irreversible. Others are concerned about a potential watering-down of consumer rights, food safety standards, rights of work or environmental protections, and the facility for corporations to sue national governments if regulations impinged on their profits.
"I've read a great deal about this. I've thought a great deal about it. And I absolutely share all those concerns expressed by those opposed to TTIP.
"A few weeks ago the French president Francois Hollande said he would veto the deal as it stands, and to become law any deal would have to be ratified by each member state. So, today, we give this pledge. As it stands, we too would reject TTIP and veto it in government."
The Prime Minister must now reject proposals to ease trade between the US and the EU, Corbyn said.
"David Cameron, make clear now that if Britain votes to remain this month, you will block any TTIP trade treaty that threatens our public services, our consumer and employment rights and that hands over power to giant corporations to override democratically-elected governments," he said.
"The EU's state aid rules, which limit the scope for governments to intervene to support our vital industries, also need to change. But so does how British governments interpret them. The steel crisis highlighted how Germany, Italy, France and Spain all did much better at protecting their steel industries.
"They acted within EU state aid rules to support their industries, whether through taking a public stake, investing in research and development, providing loan guarantees or compensating for energy costs.
"Nevertheless, the rules are too restrictive and national governments must have the powers to act to protect key industries."
Corbyn also launched a savage attack on George Osborne over his Brexit recession warnings and claimed the Tory government poses the "biggest risk" of plunging Britain into an economic crisis.
He rubbished the "prophecies of doom" and "histrionic" claims being made in the referendum campaign as he laid into the Chancellor's record on the economy.
He said: "There are just three weeks to go until the referendum vote on June 23 but too much of the debate so far has been dominated by myth-making and prophecies of doom.
"In the final stage of this referendum, as we get closer to what is expected by many to be a very tight vote, it does not help the debate over such a serious issue if the hype and histrionic claims continue or worse intensify."
He added: "Just over a week ago, George Osborne claimed that the British economy would enter a year-long recession if we voted to leave. This is the same George Osborne who predicted his austerity policies would close the deficit by 2015. That's now scheduled for 2021.
"It's the same George Osborne who said the British economy would be 'carried aloft by the march of the makers' yet the manufacturing sector has stagnated ever since - and manufacturing employment declined.
"The biggest risk of recession in this country is from a Conservative government that is failing - failing on the deficit, failing on the debt, failing to rebalance the economy and failing to boost productivity."
The criticism comes in stark contrast to the approach of Labour former chancellor Alistair Darling, who has joined forces with Osborne to accuse leave-the-EU campaigners of "making it up as you go along".
The political opposites, united in their support for the European Union, have published an open letter calling on the Brexit campaign to answer basic questions about its economic argument.
They said the campaign was putting forward "uncosted and unworkable proposals" that would damage the country.