European Commissioner for Agriculture and Rural Development, Phil Hogan, announced his intention to extend the cut-off point from June 30 to October 15.
Mr Hogan said it was an “exceptional measure” and an “unprecedented level of flexibility” for member states, including Scotland, that have struggled to process the vital payments on time.
This means that the Scottish Government will likely avoid fines of up to £125 million that could have been imposed if 95% of farm payments were not made by June 30.
In the Borders, farming businesses were due over £50m in payment last December.
Mr Lamont said this week: “Today’s news cannot be used as an excuse for any further delays in the distribution of CAP payments to farmers in the Borders.”
Elsewhere, NFU Scotland’s chief executive Scott Walker voiced a similar opinon: “Any deadline shift must not be used as an excuse by the Scottish government in delaying the payment of outstanding 2015 monies any further.”