Brussels has agreed a temporary truce with the UK on the vexed issue of meat shipments entering Northern Ireland from Great Britain, but warned it will not provide a “blank cheque” on the suspension of post-Brexit Irish Sea checks.

Following a long running spat over between the UK and the EU — dubbed the “sausage wars” — the European Commission on Wednesday approved a three-month extension to a grace period on restrictions on chilled meat exports from Britain into the region.

But Maros Sefcovic, the EU’s Brexit commissioner, said the extension should be used “in the most efficient manner to find a lasting solution”.

“A continuous rolling over [of grace periods] does not give predictability to businesses in Northern Ireland,” Sefcovic added.

The dispute over chilled meats has become a symbol of the wider struggle between Brussels and London over how to implement the Northern Ireland protocol — part of the 2019 Brexit treaty which secured the UK’s exit from the bloc. The protocol avoids the return of a north-south trade border in Ireland but creates new checks on goods travelling from Britain to Northern Ireland to ensure they do not just pass through the region and into the EU single market.

While British officials said the mood between the two sides had improved, Boris Johnson told MPs on Wednesday that the onus was on Brussels to give further ground in the coming months to reduce border checks on Britain-Northern Ireland trade.

Johnson said the EU needed to address its interpretation of the protocol and how it related to “the ban on chilled meats, the restriction on the circulation of cancer drugs, and the fact that 20 per cent of all the customs checks carried out in the whole of the EU are carried out in Northern Ireland”.

The UK has refused an EU offer for a “Swiss style” agreement to mirror EU rules on plant and veterinary products that Brussels says would remove the need for 80 per cent of checks on goods crossing the Irish Sea.

A six-month grace period for chilled meats was originally introduced last December — just ahead of the UK’s departure from the EU single market and customs union — to help businesses shift to the new Brexit arrangements and was due to expire on Wednesday.

Lord David Frost, the UK’s cabinet minister for Brexit, welcomed the “sensible extension”, the terms of which would “not require rules in the rest of the UK to align with future changes in EU agri-food rules”.

“This is a positive first step but we still need to agree a permanent solution. The chilled meats issue is only one of a very large number of problems with the way the protocol is currently operating, and solutions need to be found with the EU,” said Frost.

Simon Coveney, Ireland’s foreign minister, said he had “full confidence” that a solution would be found.

However Aodhán Connolly, director of the Northern Ireland Retail Consortium, said that while the agreement was welcome news, in “trade terms it is a peripheral matter”.

“The most pressing issue is the fate of the thousands of food products moving daily from GB to NI, which will be subject to extensive controls when that [new] grace period ends in October. We are no closer to a decision by both sides on this.”

Shane Brennan, chief executive of the Cold Chain Federation, said that nothing in the two sides’ statements pointed to “genuine progress”.

Brussels has voiced its frustration at what it claims is the UK’s unwillingness to implement the protocol in full and demanded that the British government meets its promises to set up border posts at Northern Ireland ports and allow the EU access to IT systems that trace goods entering the region.

In a further sign of improving relations, the commission on Wednesday also confirmed it will propose legislation later this year to help ease the supply of generic medicines from Britain to Northern Ireland after disruptions in the flow of medical supplies.

Brussels will also take measures to allow for the movement of guide dogs from Britain to Northern Ireland and soften rules so motorists from the UK will not need to show insurance green cards when entering the EU. “We have put together practical solutions to facilitate everyday life for citizens in Northern Ireland,” said Sefcovic. “I hope our creativity and goodwill is mirrored on the British side who can do the same.”

Separately on Wednesday, Belfast’s high court dismissed a legal challenge from senior unionists against the protocol, declaring that while the trading rules conflict with the 1800 Act of Union, the rules are lawful because they were introduced by a parliamentary act that overrides previous legislation.

The Ulster Unionist Party, the second biggest unionist party in Northern Ireland’s devolved assembly, said it would appeal against the ruling.