Brexit: What will happen in Northern Ireland?

After years of wrangling, the EU and the UK have outlined new rules aimed at preventing checks along the border between the Republic of Ireland and Northern Ireland from 1 January.

As part of a hard-won peace deal between Ireland and the UK, both governments agreed that the border between Ireland and Northern Ireland should be practically invisible - no cameras, no border posts. This was easy when both Ireland and the UK were part of the EU, and people and goods could move between the two countries unhindered.

The UK's withdrawal from the EU means a new arrangement is needed for 1 January, because of the risk that goods could be moved between the UK to the Republic of Ireland, which remains an EU member - but any change has to avoid bringing back visible border checks.

The UK and EU have agreed that checks will not take place at the border between Northern Ireland and the Republic of Ireland.

Northern Ireland will continue to follow many of the EU's rules, meaning that lorries can continue to drive across the border without having to be inspected.

However, there will be a new "regulatory" border between Northern Ireland and Great Britain (England, Scotland and Wales). That's because, unlike Northern Ireland, Great Britain won't have to follow EU rules in future.

This means some checks on goods moving between Great Britain and Northern Ireland will be needed.

The EU has very strict rules about what can enter its market when it comes to some foods such as meat, milk, fish and eggs.

From 1 January, some food products arriving in Northern Ireland from England, Scotland or Wales will need to be checked to ensure they meet EU standards - they will need to go through a border control post at sea ports, where paperwork will be checked and some physical inspections will take place.

However, in order to reduce any potential disruption, supermarkets will be given an initial three-month "grace period" where the rules will not be enforced on the food they bring into Northern Ireland. This is to give them time to adapt to the changes and to ensure supplies are maintained.

Some meat products, like sausages, will have a longer six-month grace period.

What happens after this period is unclear, and will be the subject of future negotiations.

Right now the UK and the EU are negotiating a trade deal to try to eliminate new charges - known as tariffs - from being introduced on other goods from 1 January.

However, even if those talks fail, a temporary exemption has been agreed for Northern Ireland. Known as the trusted trader scheme, the vast majority of goods going from Great Britain to Northern Ireland will not face any tariffs.

That said, there will be still some new paperwork requirements from 1 January - so businesses will need to prepare