The EU and UK are close to reaching a truce over checks on goods crossing the Irish Sea, in a move that would leave unresolved longer-term questions over the implementation of the Brexit withdrawal agreement.

The European Commission is expected to grant a three-month extension to a grace period before restrictions come into force on exports of chilled meat products from Britain to Northern Ireland, diplomats said.

Maros Sefcovic, EU Brexit commissioner, gave a relatively upbeat assessment of the prospects for a temporary understanding to be reached with London when he spoke to diplomats on Wednesday, according to people familiar with the meeting.

The EU offer of an extension would be subject to broad conditions, including UK commitments to work towards longer-term, more sustainable solutions for trade between Great Britain and Northern Ireland, and steps ensuring there are no threats to the single market.

If endorsed by the Council of the EU, the extension would mark a de-escalation from earlier this month, when Boris Johnson, UK prime minister, warned at a G7 summit that he would not hesitate to suspend parts of the Northern Ireland Brexit deal unless the EU stopped dealing with the issue in a “theologically draconian” way.

The Northern Ireland 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 avoid them passing through the region and into the EU single market.

The EU only permits trade in frozen processed meat products, and a “grace period” to allow the continued sale of British sausages, minced beef and chicken nuggets in Northern Ireland expires at the end of June.

The UK has claimed the EU wants the checks on trade between two constituent parts of the country to be applied in an unfairly restrictive way.

However, the British government is more optimistic that a temporary deal to extend the grace period will be agreed, although there has been no formal confirmation.

“There are much more positive noises we are hearing, although it’s not set in stone yet. We are expecting a three-month extension to September in line with the other grace periods,” a senior government figure said.

Lord David Frost, UK Brexit minister, told MPs on the foreign affairs select committee on Tuesday: “We have put in our proposal to extend the grace period on chilled meats which expires very soon and I know both sides are thinking very actively about that. I wouldn’t want to leave the impression that nothing is happening. Quite a lot is happening, in one or two areas there is engagement, in other areas it’s more difficult.”

Trade groups affected by the stand-off said they would welcome any move to delay the ban, but repeated warnings that, without a veterinary agreement, temporary solutions would not facilitate trade.

Shane Brennan, chief executive of the Cold Chain Federation, which represents the chilled logistics industry, said an extension was a sign of constructive dialogue, but must be used to seek solutions — specifically a veterinary agreement for meat and dairy goods.

“Temporary extensions, partial exemptions and convoluted digital processes are not enough to give businesses the confidence to start trading again. Without this it is the smallest businesses that will suffer,” he said.

Aodhán Connolly, director of the Northern Ireland Retail Consortium, said an extension would be a “good start” but political movement was required on both sides to create a stable trading environment for businesses and households in Northern Ireland.

“Business is frustrated that we can see solutions, such as a trusted trader scheme, but we haven’t had the political movement we need. An extension is a welcome move and a good start, but more needs to happen — and quickly,” he added.