Olefins and polyolefins giant Ineos has come out in support of the Brexit deal approved last week by the EU at a summit in Brussels. The agreement, said the group’s chairman, Jim Ratcliffe, “provides frictionless trade between the UK and the EU while giving the UK freedom to develop its own long-term global trading relationships that would advance the economy.”

The British tycoon, who moved operations to Switzerland in 2010, but repatriated some businesses in 2016, said the deal creates a “sensible” transition period that should allow both parties the time to develop long-term agreements.

“I have made no secret of the fact that while I have long supported the concept of a Common Market within Europe, I have never felt comfortable with the concept of ever closer union,” Ratcliffe told the UK press.

The chemical producer has said its business would face “significant risk” from a no-deal Brexit that could involve tariffs on chemicals and the potential disruption to its supply chain at ports. Director Tom Crotty told the London newspaper The Times that the group may ultimately have to shutter some of its UK assets to unite the supply chain on one side of the border.

Ineos’ biggest UK site is the Grangemouth oil refinery and petrochemicals complex in Scotland. It also operates a major petrochemicals complex at Runcorn in Cheshire, a plant in Hull producing ethyl acetate and a PVC plant at Newton Aycliffe in County Durham.

If the relationship between Britain and the EU reverted to World Trade Organization (WTO) rules, chemical products moving back and forth across the border could be hit with a 6.5% tariff s each way, Crotty said. These could cost Ineos “tens of millions of pounds.”

A bigger concern, Crotty said, is the “unquantifiable” risk from uncertain customs arrangements. Long delays at ports “would rack up costs much higher than tariff risks.” The majority of Ineos’ chemical business is conducted in the EU, so that UK plants would be at greater risk, he remarked. However, he said Ineos is unlikely to close entire UK sites, but rather “certain assets on certain sites.”

The chemical giant has been lobbying the UK government for financial support on various projects that the director has suggested it could build post-Brexit. Crotty has dropped hints that Antwerp is the favored location for a new VAM plant, but Hull could have a chance if the UK government offers incentives.