Clarification is needed from the Scottish government over what measures sheep breeders should take to avoid facing penalties for failing to comply with stringent rules over electronic tagging.
Isles MP Alistair Carmichael has called on the SNP to end uncertainty over the regulations aimed at improving animal traceability.
He wants details of scanning targets to be made public so farmers and crofters can avoid being penalised.
His call follows confirmation farmers and crofters in Scotland would be exempt from the new rules which require breeders in the EU to achieve a 100 per cent read rate of their sheep to avoid cross-compliance penalties.
But ministers at Holyrood have yet to provide MSPs and farmers with specific details on what level of compliance producers will have to reach before being fined.
Earlier this week a delegation of Scottish sheep farmers met with ministers to discuss issues relating to the new rules.
Farmers and crofters in the isles had previously warned the new rules could be unworkable and unnecessary – not least because many animals in Shetland spend their whole lives on one holding.
Mr Carmichael said: “Before the new rules were introduced I went to Brussels and warned officials that implementation would cause serious problems for farmers in the Northern Isles.
“Given the challenges posed by our geography, a 100 per cent read rate would be difficult to achieve and we faced the prospect of farmers bending over backwards to comply and still being hit with large fines.
“The fact that the EU was willing to show some flexibility on this issue was welcome but what farmers now need is certainty. Scottish ministers need to confirm exactly what the required compliance rate will be as a matter of urgency.”