Talks between Britain and the European Union to resolve problems with the Brexit agreement regarding Northern Ireland will move to London next week with the UK government warning on Saturday that "substantial gaps" remained.

A negotiating team from the European Commission will travel to London on Tuesday "for several days of intensive discussions", according to a statement issued by London on Saturday.

British minister David Frost and EU Commission Vice President Sefcovic are due to meet for talks at the end of the week to "take stock and assess progress so far".

London added that talks over the previous days had been "constructive" but that "substantial gaps" remain.

The EU put forward a host of proposals, including reduced customs checks and paperwork on British products intended for Northern Ireland
The EU put forward a host of proposals, including reduced customs checks and paperwork on British products intended for Northern Ireland AFP / Paul FAITH

Brussels has put forward a raft of proposals to try and ease tensions within the loyalist community over the Northern Ireland Protocol, the part of the Brexit deal that deals with the British province.

The proposals include reduced customs checks and paperwork on British products intended for Northern Ireland, which loyalists complain are driving a wedge between Belfast and London and building momentum for the republican push for a united Ireland.

Anti-EU protestor in London's Trafalgar Square
Anti-EU protestor in London's Trafalgar Square AFP / Adrian DENNIS

Despite moving on customs checks, the European Union has said it will not accept London's demands for an alternative arbitrator to settle post-Brexit trade disputes involving Northern Ireland.

As a result, Britain is threatening to trigger the protocol's Article 16, which provides both parties with unilateral power to take action if they believe the agreement is causing "serious economic, societal or environmental difficulties that are liable to persist".

"There's been plenty of speculation about governance this week but our position remains unchanged: the role of the European Court of Justice in resolving disputes between the UK and EU must end," a British government source said in Saturday's statement.

"We need to see real progress soon rather than get stuck in a process of endless negotiation because the issues on the ground in Northern Ireland haven't gone away.

"Whether we're able to establish that momentum soon will help us determine if we can bridge the gap or if we need to use Article 16 to safeguard the Belfast (Good Friday) Agreement".

That agreement ended decades of violence between republicans who want a united Ireland, and loyalists who want it to remain part of the United Kingdom.

Designing the protocol was a major source of friction in Britain's drawn-out divorce from the EU after it voted to leave the bloc in 2016.

Both sides say they want to preserve peace and stability by avoiding a hard border on the island of Ireland, which is split between EU-member the Republic of Ireland and the UK province.

To achieve this, Northern Ireland was given unique status as a member of both the UK and the EU single market.

This required new checkpoints at ports to prevent goods from England, Scotland and Wales getting into the EU via Ireland -- a key source of anger among unionists.