The DUP will attempt to amend the Internal Market Bill to ensure the UK sets the rules on state aid in Northern Ireland.

The Northern Ireland Protocol sets out that EU state aid rules will apply to commerce.

State aid means a government cannot subsidise a product to allow it to be sold more cheaply in other parts of the EU to the potential detriment of businesses there.

The DUP’s Westminster chief whip Sammy Wilson lambasted former prime ministers Sir John Major and Tony Blair after they warned the UK’s latest proposals could undermine the 1998 Belfast Agreement.

He said: “The Internal Market Bill is far from perfect and that’s why we will table amendments to the Bill.

“The suggestion by the hero of the peace process brigade that the Bill rips apart the Belfast Agreement is complete and utter bunkum without any factual basis.

“They need to explain how making it easier for Northern Ireland to do business with our biggest market undermines the Belfast Agreement.

“They need to explain how Northern Ireland companies having less paperwork undermines the Belfast Agreement.

“They need to explain how our amendment which would ensure the UK sets the rules on state aid in Northern Ireland undermines the Belfast Agreement.

“Such a tool is vital to help us fend off predatory behaviour from our nearest competitor.”

The East Antrim MP said the Belfast Agreement contained one substantive mention about the Irish border and that related to Army demilitarisation – which has already happened.

He added: “The Belfast Agreement however is about respecting consensus, something which the Withdrawal Agreement ignored and drives a coach and horses through.

“Blair and Major were less outspoken about the impact of a trade border between Northern Ireland and the rest of the UK despite its obvious impact on our economy and relationships in Northern Ireland.

“The Internal Market Bill as published is not the finished product but it is a massive step forward for business in Northern Ireland.”

Stormont Assembly member Caoimhe Archibald said the UK Government is acting in bad faith and has shown clear intent to disregard the Northern Ireland protocol in the Withdrawal Agreement.

The Sinn Fein spokeswoman on Brexit called for this breach of international law to be debated in the Assembly on Monday.

She said: “Publication of the Internal Market Bill by British Government shows its clear intent to disregard the protocol in the Withdrawal Agreement with huge implications for the Good Friday Agreement and for our economy, businesses, jobs and livelihoods.

“The British Government is clearly acting in bad faith and the international community can see that and have made it clear with both the European Commission and leading US political figures calling it out.

“The protocol has been agreed to, it is part of an international treaty and it cannot be wished away.”