Unilever's CEO insists it has nothing to do with Brexit but unions say Britain is becoming less competitive.
Britain's third biggest company Unilever picked Rotterdam over London for its main headquarters on Thursday in a blow to Prime Minister Theresa May's government a year before Brexit.
The Anglo-Dutch maker of Dove soap, Lipton teas and Ben & Jerry's ice cream launched a review of its dual-headed structure in 2017 after fighting off a 118 billion euro takeover from Kraft Heinz.
That triggered a battle between Britain and the Netherlands.
Under the new plan, Unilever will continue to be listed in London, Amsterdam and New York, and will divide into three divisions, keeping two based in Britain. That will enable it to retain its 7,300 staff in the United Kingdom.
The company said the decision to end 88 years of two parent-ownership was not linked to Brexit or any form of protectionism, but would simplify its structure and facilitate acquisitions.
However, British unions and supporters of EU membership bemoaned what they said was a deterioration in Britain's competitiveness at a time when tax code changes and strong anti-takeover laws have made the Netherlands increasingly attractive.
"Let me categorically say that this had nothing to do with Brexit," Unilever Chairman Marijn Dekkers told reporters.
"The board takes a 30 to 50 year decision. We think both countries are highly attractive investment climates and we will continue to invest in both countries as a result of this," the Dutchman added.
It is unclear whether Unilever can remain in the FTSE 100 Index of leading UK stocks, a decision which could hit its shares if tracker funds are forced to sell.
In early 2017, the company - which had been thought to be too big to take over - managed to fight off one of the largest corporate bids ever made, but had to placate investors with a plan to boost profits and reinvigorate the group.
The short-lived bid battle has had widespread repercussions.
In the weeks after the offer, Chief Executive Paul Polman said Britain, known for promoting one of the most open economies in the world, should do more to protect national champions.
Unions in Britain have noted that Dutch companies have stronger powers to fight off unwanted takeovers, as seen last year when paint maker Akzo Nobel fended off a 26.3 billion euro bid from U.S. rival PGG Industries.
Unilever said it did not expect any significant tax changes as a result of the deal. It said it had chosen the Netherlands because the Dutch company currently accounted for 55 percent of the group and those shares traded with greater liquidity.