THE Irish Republic and Brussels have urged the UK Government to honour all the terms of the Withdrawal Agreement.
The statements came yesterday, after reports suggested that Prime Minister Boris Johnson had ordered his Brexit team to find ways to "get around" the Northern Ireland Protocol.
But Downing Street insisted the UK would "comply with our obligations" under the deal struck with Brussels, and said it would require only "limited changes" to Great Britain-Northern Ireland trade.
The Sunday Times reported that officials in Taskforce Europe are seeking to evade Irish Sea checks on goods passing from GB to NI.
NI Secretary Brandon Lewis, on a visit to Londonderry yesterday, cautioned against getting "caught up in rumours and stuff in the press", and reiterated the Government's insistence that there would not be a border down the Irish Sea.
Speaking in Dublin earlier yesterday, Taoiseach Leo Varadkar said the Withdrawal Agreement is an international treaty and he expects the UK to "honour that in full". He said there can be "no backsliding" and urged Mr Johnson's Government to focus on the next phase of negotiating a free trade agreement.
"We totally understand why they may want to minimise any checks at the ports and airports in Northern Ireland. We want to do that, too. But the agreement clearly says if there have to be checks anywhere, they would happen at the ports and airports in Northern Ireland rather than on the land border between North and South," he said.
"So, I am saying to the British Government, there can be no backsliding on the Withdrawal Agreement, let's not even go there and let's focus instead on what should be the next phase, which is negotiating a free trade agreement between the European Union and Ireland and the UK so we can protect jobs and our economy."
Brussels said the Withdrawal Agreement must be effectively implemented - and cautioned that respecting legal obligations would be "very important" for establishing trust between the UK and EU in future negotiations.
Dana Spinant, deputy chief spokeswoman of the European Commission, told reporters: "The Withdrawal Agreement has been signed and ratified by both sides and as such it must be effectively implemented. That includes, of course, the Protocol on Northern Ireland and all its constituent parts.
"Of course in this context, as in all others, we would expect our partners to respect their international obligations under their national law and under international law - that includes of course the Withdrawal Agreement, which has legal force."
She added: "Respecting our legal obligations is very important for establishing trust between two partners in a negotiation."
Mr Johnson's Cabinet will meet today to sign off on the proposals, it was reported, which are expected to be presented in Parliament and published online on Thursday.
The Withdrawal Agreement between the UK and EU leaves NI within the UK customs area, but all EU procedures will apply to goods arriving there.
Mr Lewis was asked about the issue on his first visit to Londonderry since replacing Julian Smith as Secretary of State.
"I think it's safest not to get too caught up in rumours and stuff in the press over the weekends, we are focusing on our main job," he said.
"We have always said we want to make sure there is unfettered access between GB and Northern Ireland, we've always as a Government obviously gone by the rule of law and we will continue to do that. We want to make sure that the United Kingdom is one whole Union, and one that is good for business across the United Kingdom.
"We've always said there will not be a border down the Irish Sea, there will be unfettered access for business."
The Prime Minister's official spokesman said: "The protocol specifically allows the UK to ensure unfettered market access for goods moving from Northern Ireland to GB. The UK signed the Withdrawal Agreement including the Protocol last month; we will comply with our obligations."