The Labour Party has said it would ensure there is no post-Brexit regulatory border down the Irish Sea if it is elected to power.
Launched on Thursday, the party's manifesto, described as the most "radical and transformative" set of policies for decades, includes a section dedicated to Northern Ireland.
The party has also said there would be no return to a hard border between Northern Ireland and the Republic.
Under Boris Johnson's Brexit deal negotiated with the EU, there would effectively be a regulatory border implemented down the Irish Sea, as Northern Ireland would continue to follow EU rules on goods and agriculture, while the rest of the UK would not.
To ensure these rules are followed, new checks would be needed on goods coming from Great Britain to Northern Ireland that are at risk of travelling on to the Republic.
Many unionists have criticised the PM's deal for creating an "economic united Ireland", however it has been backed by the DUP.
The Labour Party's manifesto, however, pledges to negotiate a new deal with the EU that would mean there would be no regulatory border.
"A Labour government will also protect Northern Ireland and its people in any future Brexit outcome by ensuring that there is no return to a hard border between Northern Ireland and the Republic of Ireland or the creation of a regulatory border down the Irish Sea," the manifesto states.
The party hopes to achieve this via the whole of the UK having "close alignment" with the EU single market, however the precise details of this are not spelt out.
Labour also promises a "permanent and comprehensive UK-wide customs union" to protect the UK's manufacturing industry and allow for joint UK-EU trade deals.
Elsewhere in their manifesto, Labour has pledged "as a priority" to secure the return of the Northern Ireland Assembly and invest an extra £1.9 billion to "end austerity and rebuild public services in Northern Ireland".
The party also stated it would bring forward and implement a Bill of Rights for Northern Ireland, as outlined in the Good Friday Agreement.