Farming unions continue to press the government for the need to find solutions to the ongoing biofuel problem.
Both the NFU and NFU Scotland have received hundreds of reports of filter blocking issues in agricultural vehicles and machinery.
The issues began in August 2019 and are suspected to be related to the quality and possible composition of red diesel.
The reports are of fuel filters in farm machinery blocking up unusually quickly, needing to be replaced far more frequently than expected, the NFU explains.
The substance found to be blocking the filters varies between reports but commonly consists of a black slime or a clear wax.
Affected machinery includes a range of makes and models, costing members both time and money.
In an update released on Friday 10 January, NFU Scotland said it is currently pursuing 'high level solutions'.
Last month, the union wrote to Secretary of State for Transport, Grant Shapps MP that was shared with Scottish government.
Meanwhile, fuel manufacturer Petroineos announced at the end of last year to reduce biofuel content as a short-term solution.
Now the government has been urged to broker a fuel replacement scheme to enable farmers who have problematic fuel on farm to receive a fuel uplift and refill of alternative fuel suitable for their needs.
A review of the specification and testing protocols is also needed, according to NFU Scotland, as this will ensure fuel produced within the UK is fit for purpose and reliable.
Further research into the behaviour of recycled oil and animal fats within diesel is required, and to assess if specific fats should be excluded from diesel, the group added.
NFU Scotland Policy Adviser, Zoe Meldrum said: “Fuel problems remain a top priority for our members and resources continue to be dedicated towards finding practical solutions and apply lessons from this event to ensure fuel issues such as this cannot impact agriculture again.
“Members’ evidence has been fundamental in understanding the problem and more than 400 contacted NFUS in November and December and we thank them for the invaluable information.
“We are asking members who are continuing to have problems to complete the survey (available here) when they experience a problem.”
It comes as representatives from the NFU and NFU Scotland attended a meeting with industry experts in December to discuss the specifications, standards and testing protocol of fuel.
A commitment was made to create a dedicated taskforce which will assess filter blocking within agricultural vehicles.