The UK's foreign secretary Boris Johnson has dropped a heavy hint that the UK is likely to leave the EU customs union as part of its planned Brexit settlement.
Mr Johnson, speaking in an interview with a Czech newspaper, said the country will "probably" need to leave the customs union after it quits the EU, while adding this issue will be settled during the formal negotiation process.
Exiting the EU customs union has the potential to create new barriers to UK-EU trade post-Brexit, though trade secretary Liam Fox has previously pointed out that it could also make it easier for Britain to negotiate independent trade deals with non-EU countries.
Many British government ministers are keen to cut ties with the single market in order to regain UK control of immigration laws, a key point of principle raised during the EU membership referendum campaign.
Jonathan Roberts, head of communications for the UK Chamber of Shipping, responded to Mr Johnson's comments by suggesting the reimposition of customs checks would have a "profoundly negative" effect, citing the increase in trade volumes since the customs union was introduced.
He said: "If we do leave the customs union, it will be imperative that both UK and EU negotiators create a bespoke deal to allow trade to continue to move freely through our ports."