Brexit: What's the Northern Ireland Protocol?

The UK government wants urgent changes made to the Brexit agreement known as the Northern Ireland Protocol.

Since coming into force at the start of the year, the protocol has prompted disagreements with the EU - including a row over transporting sausages and other chilled meats.

The Northern Ireland Protocol helps prevent checks along the land border between Northern Ireland (in the UK) and the Republic of Ireland (in the EU).

During Brexit negotiations, all sides agreed that protecting the 1998 Northern Ireland peace deal (the Good Friday agreement) was an absolute priority.

Part of that meant keeping the land border open and avoiding new infrastructure such as cameras and border posts.

This was easy to do when both Ireland and Northern Ireland were part of the EU, because they automatically shared the same EU rules on trade and no checks were needed on goods travelling from one country to another.

However, a new arrangement was needed after Brexit.

The EU requires many goods - such as milk and eggs - to be inspected when they arrive from non-EU countries, while some products, such as chilled meats, aren't allowed to enter at all.

Under the protocol it was agreed that Northern Ireland would continue to follow EU rules on product standards (known as the single market) to prevent checking taking place along the border. Checks would instead take place on goods entering Northern Ireland from England, Scotland or Wales.

Inspections take place at Northern Ireland ports, and customs documents have to be filled in.

This has prompted criticism that a new border has effectively been created in the Irish Sea.

The agreement came into force on 1 January 2021 and is now part of international law.

Under EU food safety rules, chilled meat products are not allowed to enter the single market from non-member countries such as the UK.

That means sending sausages from Great Britain to Northern Ireland is - in theory - no longer allowed.

However, a grace period has been in place since January where the rules don't apply.

That period, which was due to end on 30 June, has now been extended until 30 September - but there is still no agreement on how to resolve the dispute in the long term.

The UK had previously warned it was ready to ignore the rules if an extension was not granted, even though it signed up to them when it negotiated the Northern Ireland Protocol.

Despite signing up to the agreement, Boris Johnson says the protocol represented a huge compromise by the UK and has accused the EU of applying it too rigidly.

Now, the UK government wants to get rid of most of the checks, and reduce the customs procedures, in order to allow goods to flow more freely.

It also wants to remove the role the European Commission and the European Court of Justice have in overseeing how the protocol works.

And it is calling for the EU to agree to a "standstill" arrangement on the grace periods, and for the EU to freeze legal action, while negotiations are held.

The UK government has urged the EU to look at its proposals "with fresh eyes".

The EU has been critical of the UK's stance and has insisted it must implement the terms of the protocol.

It says it is ready to continue searching for "creative solutions", but it will not agree to a renegotiation.

It has already launched legal action against the UK, which could end up with substantial fines.

The legal move was in response to the UK's decision in March to extend a separate grace period for supermarkets until 30 September. This grace period was only meant to last for three months to allow supermarkets to adapt to the new regime at the start of the year.

The EU said the UK's unilateral action broke international law because it wasn't consulted.

The UK government says that "circumstances exist" to justify the use of Article 16 of the protocol. This allows either side to suspend any part of the agreement that causes "economic, societal or environmental difficulties".

However, the UK says it won't trigger it before holding talks with Brussels.

The EU announced it was intending to use Article 16 earlier in the year over its plans to introduce export controls on vaccines produced in the EU. However, faced with widespread criticism, the EU changed its mind within hours.

As well as problems with trade, there are also political and security concerns.

Checks were temporarily suspended at the start of the year over what were described as "sinister" threats to some border staff checking goods.

Unionists are strongly opposed to the checks because they don't want Northern Ireland to be treated differently to the rest of the UK.

There have also been a series of demonstrations and protests against any kind of border in the Irish Sea.