BRUSSELS, Oct 13 (Reuters) - The European Union offered Britain a package of measures to ease the transit of goods to Northern Ireland, but it looked unlikely to end tensions over post-Brexit trading rules for the province as it stopped short of the overhaul that London has demanded. The EU"s executive said the measures could halve customs paperwork and cut checks on meat, dairy and other food products coming to Northern Ireland from mainland Britain by 80%. New EU rules would ensure the flow of medicines, notably generics, was not disturbed. "We have completely turned our rules upside down and inside out to find a solid solution," European Commission vice-president Maros Sefcovic said of the medicines proposal. While remaining part of the United Kingdom, Northern Ireland has stayed in the EU"s single market for goods since Britain"s departure from the EU, meaning its exports to the rest of the 27-nation bloc face no customs checks, tariffs or paperwork.European Commission vice-president Maros Sefcovic, who oversees post-Brexit relations with Britain, has said the arrangement gives Northern Irish businesses the best of both worlds. However, the result is an effective customs border in the Irish Sea, disturbing trade from the rest of the United Kingdom to Northern Ireland and angering the province"s pro-British unionists. Sefcovic told Reuters he believed the proposals "ticked all the boxes" by resolving problems and keeping open Northern Ireland"s border with EU member Ireland. "This new alternative implementation of the protocol... also takes care of the sausages," he said, referring to talk of a "sausage war" prompted by the EU ban on importing certain meat products. Sefcovic said Northern Irish people would have access to the sausages they preferred. Sefcovic said the package should not be seen as a "take it or leave it" offer, but the foundation for joint agreement with Britain. However, there would be no next package if this was rejected. The Commission says that, in return for concessions, the EU wants proper sharing of live data, reinforced monitoring of supply chains and labelling to ensure British products do not slip into the EU single market via a Northern Ireland back door. The Commission will also set out plans to make greater efforts to explain its position to and involve people in Northern Ireland. However, the executive Commission will not open up for renegotiation the protocol which governs Northern Ireland"s unique trading position, leaving Brussels and London on a potential collision course.A British government spokesperson said the next step should be intensive talks to see if there was common ground, adding that "significant changes" must be made, including to governance of the protocol. Brexit Minister David Frost, whom Sefcovic hopes to meet on Friday, said he would look at the EU proposals constructively. "We"re beginning a negotiation, and we"ve got a track record of reaching successful outcomes in negotiations despite the predictions that we would not, and I hope we"ll do so again this time," he told Britain"s House of Lords on Wednesday afternoon. Northern Ireland"s largest pro-British party, the Democratic Unionist Party, said the EU proposals were a starting point but fell short of the fundamental changes needed. Northern Irish businesses welcomed "signs of movement" but said they were waiting to see the detail. read more Irish Prime Minister Micheal Martin told Newstalk radio the EU had listened to legitimate concerns about the protocol and was in "solution mode" and the British government had a responsibility to be in that mode too. "It takes two to tango," he said. Frost said on Tuesday that London would be ready to discuss the proposals "whatever they say", but also demanded a new "forward-looking" protocol, one without oversight from European judges. read more On Wednesday, he denied EU charges that Britain had abruptly moved the goalposts and said it had been clear on its stance towards the position on the European Court of Justice since July. Sefcovic said oversight by the court was the price of access to the European single market, which Northern Ireland enjoys.