As it come under attack from elements in the Conservative party and Jeremy Corbyn claimed it was defunct, BIFA’s director general Robert Keen, representing the country’s forwarders, said the latest Brexit plan was “complex and untested.”

It is the most comprehensive and cogent proposal put forward by the UK Government to date and is a useful basis for negotiation with the EU,” he said.

The white paper recommends new protocols between the soon-to-be-separate markets for military cooperation, immigration and trade.

Forwarders will be crossing their fingers that these somewhat “soft” proposals for trade-relations will come to fruition, he said.

Yet Theresa May yesterday struggled to explain how her post-Brexit customs plan will work, during a difficult appearance before a Commons and eventually seemed to concede that elements of the plan were still to be decided.

MP’s questioned how mutual trade in a future era of potentially different tariffs would work, noting that the Brexit white paper says Britain is “not proposing that the EU applies the UK’s tariffs and trade policy at its border for goods intended for the UK”.

This is a key contradiction for May’s “facilitated customs arrangement”, after she accepted on Monday an amendment to the customs bill that said the UK could not collect duties on goods on behalf of the EU unless there was a reciprocal arrangement.

May said there was no disconnect, insisting the white paper allowed for reciprocity. She said it proposed a method under which any varying tariffs would be collected for goods arriving in the UK destined for the EU, and vice versa.

One proposal in the white-paper calls for a “common rulebook,” to remove the need for time-consuming checks on cross-border cargo, which appeals to the logistics sector. 

Continuing objections are likely to result in changes to the proposed “facilitated customs arrangement” that would have Britain remain in the EU customs union requiring British and European tariffs for goods entering Britain.