A review into EU subsidies distributed by Westminster which Scottish ministers believe are "owed" to Scottish hill farmers has been delayed.

Scottish Rural Economy Secretary Fergus Ewing said the delay, confirmed in a letter from the UK Government, is "completely unacceptable".

EU Convergence Uplift payments of £190m to the UK were triggered due to the low rate of Common Agriculture Policy (Cap) payments given to Scottish hill farmers.

Only Scotland qualified for the payments, aimed at distributing the subsidies more fairly based on average euros per hectare, as England, Wales and Northern Ireland are all above the threshold.

However, so far the UK Government has allocated around £30m of the uplift payments to Scotland, with the rest being distributed around the UK.

Now an independent review into the uplift payments, announced by UK Environment Secretary Michael Gove last year, has been delayed.

Mr Ewing said: "This delay is completely unacceptable.

"Scottish hill farmers are owed £160m, which the UK Government has repeatedly ignored.

"I have been clear throughout that the money was earned in Scotland, and quite frankly should be returned to Scotland."

He said the demand is about setting a precedent for future agriculture funding within the UK.

"Having already secured the review and agreed its independent chair, it is disappointing to learn that the review is being kicked into the long grass," Mr Ewing added.

A Defra spokeswoman said: "We are in discussion with HM Treasury about this review.

"It is essential that it is considered alongside wider funding implications in Scotland, Wales and Northern Ireland as we leave the EU."

She said farming support allocations have been guaranteed in cash terms until 2022, adding: "Ministers have consistently said we will ensure all parts of the UK are treated fairly and their circumstances taken into account."