The BBC’s Analysis Editor Ros Atkins examines whether post-Brexit border checks were to blame for disruption at the Port of Dover at the weekend and to what extent.

The UK asked for an European Union external frontier, similar to the hard borders the EU has with Russia and Turkey, to take effect in Kent.

Since the new year, the impact of Brexit has had a clear effect on every stage of the logistics process... According to new research, 50% of UK business decision makers felt that Brexit uncertainty had negatively impacted their supply chain in the last five years, with this only set to increase as the full effect of Brexit becomes clear.

At 23:00 on New Year's Eve a new EU trade border was effectively created in Northern Ireland's ports. / The first of these grace periods is set to expire at the end of March and businesses are already anxious about what comes next.

A sea border would mean checks at major ports in Great Britain and Northern Ireland, such as Holyhead, Liverpool, Belfast and Larne.

Boris Johnson, the front-runner to be Britain’s next prime minister, has raised the prospect of a shock for the world’s fifth-biggest economy by pledging to leave the European Union on Oct. 31 without a transition deal if necessary.

As the possibility of a no-deal Brexit scenario increases, and the government publishes its “no-deal preparedness” notices, it is worth taking stock of the sheer variety of problems that would arise with a no-deal Brexit – and the devastating consequences that would arise from such a legal limbo. Here’s what we know so far.