The Welsh government has warned Number 10 that continued delays to the introduction of EU import checks are putting Welsh farmers at a disadvantage.
In a letter to the UK government, Wales' rural affairs minister said the delays were also putting the UK's collective biosecurity at risk.
Checks on EU imports have been delayed four times, with the latest setback announced last month.
The government had initially planned to enforce them in January 2021 at the end of the Brexit transition period.
The subsequent failure to fully implement Border Control checks has meant EU food and agricultural imports are not subject to the rigorous checks placed on UK exports.
The government said that controls will be delayed until a digital solution is created, with a target introduction date by the end of 2023.
Farming industry groups say the checks are crucial to the UK's biosecurity, animal health and food safety, and without them they leave farmers at risk.
The NFU called the latest delay ‘unacceptable’, while the Farmers' Union of Wales said the setback was a 'global disgrace'.
Lesley Griffiths, Wales' rural affairs minister, said in her letter that she was 'very concerned' the farming sector in Wales would be placed at a disadvantage.
“There will not be a level playing field for Welsh producers, who are subject to costly and time-consuming EU export checks and regulatory requirements, whilst their EU competitors continue to benefit from the lack of any such regulatory checks."
She said the Welsh government also shared concerns voiced by the British Veterinary Association in relation to risks of incursion of exotic diseases.
“Continued delays to the introduction of EU import checks are a risk to our collective biosecurity, a risk which grows with time," Ms Griffiths added.
"The lack of access to EU traceability, disease notification and emergency response systems further compounds this risk."
In the letter, the farming minister emphasised the importance of addressing biosecurity issues on a GB-wide basis.
“Given the uncertainty following the UK government’s announcement, we need our officials to urgently work together to collectively agree a risk-based approach to managing biosecurity risks."
She also reiterated the protection of biosecurity is a devolved matter and, whilst a GB-wide approach is preferable, the future borders regime to protect public, animal and plant health must meet the needs of Wales.
Wales' Economy Minister Vaughan Gething has also written to the UK government to call for Welsh ministers to be involved in discussions on import controls.
He reiterated that any expenditure on border controls following Brexit should be funded by the UK Treasury.