The government must 'double efforts' to unlock 'damaging' post-Brexit loss of trade with the rest of the EU, NFU Scotland has said.
The call comes following the recent resumption of Scottish seed potato trade with Northern Ireland, which had been halted since Brexit.
However, sales of seed potatoes to the EU remain blocked following Brexit, which saw valuable trade in UK seed potatoes to all European markets lost overnight.
Before the UK left the bloc, Scotland sold an estimated 22,000 tonnes of seed potatoes to European customers.
NFU Scotland said the UK government must 're-double its efforts to resolve this impasse'.
The Windsor Framework agreement and the introduction of ‘green’ channels for goods traded between Scotland and NI saw sales of seed potatoes specifically recognised in the text of the agreement.
That was a significant breakthrough, and 30 September marks the re-opening of the Northern Irish market for Scottish growers.
However, NFU Scotland said the overnight loss of the European market for Scottish seed was "a very damaging post-Brexit consequence".
The union's vice president, Andrew Connon said: “With trade in seed potatoes to the rest of Europe still denied, we continue to lobby both UK government and the EU to re-establish this hugely important trade link.
“It is widely known that potato stocks in Europe are now under threat due to plant disease pressures and it is time that the EU Commission listened to its member states who are desperately in need of fresh high health Scottish seed potatoes.
“The lack of availability to high health seed potatoes to grow healthy crops, compounded by some extreme weather, is having an impact on potato supplies and availability across Europe.
“Common sense and commercial reality need to prevail over political gamesmanship.”
Gordon MP Richard Thomson has welcomed the 30 September date confirmation for the restart of seed trade, but reacted 'with disbelief' that the UK government hasn’t raised the issue of exports to the EU since March.
The SNP MP said: “Having a date for the resumption of seed potato exports to Northern Ireland is undoubtedly welcome and provides certainty where previously there was none.
“However, the admission from Defra that the issue of lifting the ban on exports to the EU has not been discussed for nearly six months is absolutely astounding.
"I worry that it provides an indication of the importance – or lack of – that the UK government attaches to restoring Scottish seed potatoes – renowned the world over for their high quality – to their rightful export markets."
He said it was 'simply unacceptable' that producers across Scotland have had to endure the disruption of being able to get seed potatoes into another part of the UK.
"We find Defra has effectively been asleep at the wheel for months when it should have been driving the negotiations to get our markets back," Mr Thomson added.