UK prime minister Boris Johnson may not meet his promises to "take back control" in future post-Brexit trade negotiations, the Institute for Government said in a report on Monday.
The "Trade and Regulation After Brexit" study claims that "regulatory autonomy" would remain out of reach due to stronger countries demanding changes to Britain's standards.
Further tensions between London and Edinburgh over food standards were 'high', the report read, citing a potential trade deal with Washington, which could see chlorinated chicken enter British supermarkets.
"The UK has made an unforced error in entering talks with the US, Australia, New Zealand and Japan before reaching such an understanding at home. It should seek to correct it as soon as possible," the report said.
The report warns ministers that Britain could "easily fall victim" to nations “threatening to collapse the talks if they do not get what they want”, including being "vulnerable to challenge" at groups such as the World Trade Organisation.
It also warned ministers of being "pushed into making concessions it shouldn't" and damaging the British union, among others.
“The only thing we have to fear is fear itself. I think there is a huge opportunity. Do free trade deals, believe in ourselves,” Mr Johnson said ahead of the 2016 Exiting the European Union referendum.
Current deals being negotiated with the US and Japan would only contribute roughly a combined 0.6 percent to the UK's GDP, figures from the Treasury revealed.
The news comes after newly appointed Russian envoy to the United Kingdom, Andrei Kelin, said in an interview that UK policy was becoming "more and more linked to the policy of the [US], and this is worrying us a bit".
Britain would have to "submit certain interest" to the US to secure post-Brexit trade talks, the diplomat added.