The EU is expected to outline its response to UK demands to alter post-Brexit arrangements for Northern Ireland following this summer’s tense “sausage war” between the two sides.

European Commission vice-president Maros Sefcovic is set to hold a news conference on Wednesday afternoon in which he will deliver Brussels’ verdict on UK proposals for the Northern Ireland Protocol.

The senior EU politician will speak a day after UK Brexit minister Lord Frost demanded a “new” Protocol – which was designed to avoid a hard border on the island of Ireland – be thrashed out between London and Brussels as he claimed the current arrangements are “not working”.

In a speech in the Portuguese capital Lisbon on Tuesday, Lord Frost delivered a series of barbs at Brussels as he accused the EU of being an organisation “that doesn’t always look like” it wants the UK to succeed.

The Conservative peer – who has passed a suggested new legal text to the EU – also called for the removal of the European Court of Justice (ECJ) from oversight of the Protocol.

And he reiterated his threat that the UK could suspend post-Brexit arrangements for Northern Ireland – which were designed to prevent a hard border on the island of Ireland – by triggering Article 16 of the Protocol.

Ahead of Mr Sefcovic’s own response to Lord Frost’s demands, another senior European Commission figure expressed his hope that the EU’s own proposals would be met with a positive reception in London.

Frans Timmermans, a fellow European Commission vice-president to Mr Sefcovic, told Sky News: “We just want to find practical solutions for the problems of the people and businesses of Northern Ireland.

“And we’ll be in that mode tomorrow when we discuss it in the College of Commissioners and we will continue to follow that line.

“We know that there are some objective difficulties in Northern Ireland for citizens and businesses and we want to be part of solving those and we will make some practical propositions to solve them.

“Let’s try and find practical solutions to this and let’s not try and politicise it too much.”

Please use Chrome browser for a more accessible video player

Asked about the UK’s threat to trigger Article 16 and suspend the Protocol, Mr Timmermans added: “That’s up to them to do, that’s what they could do if they want to, but our focus is on finding solutions.

“How do you help the people in Northern Ireland and the businesses in Northern Ireland by triggering Article 16?

“Why not just try and find practical solutions? We will make some propositions tomorrow and hopefully they will be met with a positive reaction from the British side.”

However, Lord Frost’s demands to remove the ECJ from oversight of the Protocol met resistance elsewhere within the EU.

Irish deputy prime minister Leo Varadkar warned the UK’s requests would be “very hard to accept” in Brussels.

“The role of the European Court of Justice is there to adjudicate the rules of the single market,” he told a news conference in Dublin.

“I don’t think we could ever have a situation where another court could decide what the rules of the single market are.”

Subscribe to the All Out Politics podcast on Apple Podcasts, Google Podcasts, Spotify, Spreaker

DUP leader Sir Jeffrey Donaldson, whose party never supported the Protocol due to its imposition of checks between Great Britain and Northern Ireland, has warned both the UK government and EU against “tinkering around the edges with temporary fixes”.

“The Protocol does not have the support of a single elected unionist in Northern Ireland. If it is not replaced, then it will condemn Northern Ireland to further harm and instability,” he said.

“We need a long-term solution which will then allow us all to plan and get back to focusing on fixing our public services rather debating the Protocol.”