LONDON, Nov. 6 (Xinhua) -- Britain might face huge challenges in external trade talks even if it could take control of the trade policy after Brexit, experts warned at the second UK Trade Policy Observatory (UKTPO) conference in London Wednesday.

The UKTPO is a partnership between the University of Sussex and the Royal Institute of International Affairs, commonly known as Chatham House.

When Britain is outside the European Union (EU), the country might have declining voice on the trade negotiation table with countries like the United States, argued Peter Holmes, trade expert and Fellow of the UKTPO at the University of Sussex.

Aligning British rules with those of the United States would create divergences with the EU and inevitably create extra frictions at the UK-EU border, Holmes pointed out in his recent paper on the future of UK-U.S. trade.

To transfer the EU law into British law would result in a large body of new legislation for trade in the country, said Emily Lydgate, a senior lecturer in law at the University of Sussex.

Taking food safety as an example, with respect to external trade agreements, such as with the United States, she said food safety legislation gives ministers broad discretion to make future changes.

"Is it possible to have unified approach to food safety between devolved nations in trade negotiations?" she raised the question, considering Northern Ireland will likely remain aligned with the EU while Scotland wishes to maintain regulatory alignment with the EU.

Other experts from the University of Cambridge, the Bank of England, and other institutions also expressed their concerns on the unpredictable trade policy and lack of trust in trade talks with the United States.

The annual UKTPO conference focused on the legal areas of trade policy this year, bringing together experts from academia, government and business.

Topics in the conference, among others, included blockchain's influence on trade in services, China's role in international trade, and current trade tensions.