To the disappointment of some farmers who believe the Highland Show is not an appropriate venue for a political tussle, those for and against an independent Scotland set out their stalls.

First out of the blocks yesterday was Environment Secretary Richard Lochhead, who made the case for voting for independence in the referendum to be held on September 18, 2014.

Addressing an invited audience in the Scottish Government Pavilion, he said: "I have heard some wild claims about the impact independence will have on our successful food and drink industry.

"But many businesses tell me that the biggest threat for our food and drink industry is indeed a forthcoming referendum – but not the one in 2014, but the UK's proposed referendum on EU membership in 2017.

"The real threat to Scotland's food and drink industry is if, by remaining part of the UK, we are taken out of Europe." Many farmers are worried that protracted negotiations for an independent Scotland to become a full member of the EU could disrupt the flow of vital farm support from the CAP, worth around £600 million annually.

Mr Lochhead explained: "Between Referendum Day in 2014 and Independence Day in 2016, Scotland will be negotiating independence whilst part of the UK and within Europe.

"The UK's own chosen legal expert, Professor James Crawford, of Cambridge University, has given his view that it would be "realistic" to expect negotiations to have been concluded by that date."

That view was rejected by Lib Dem MEP George Lyon, who was president of NFU Scotland when he was a tenant dairy farmer on Bute.

Speaking at a meeting held by Better Together campaigners in the Highland Hall, Mr Lyon stressed: "Negotiating our way back into the EU will be difficult and could take many years."

Mr Lyon confirmed farmers were worried about the impact lengthy negotiations could have on support payments, saying: "What we are finding is that people have real questions, particularly on EU support. The truth is that we simply do not know what independence would mean for Single Farm Payments and other support that is so important to farm businesses.

"Farmers need to know the facts about what splitting from the UK would mean for them." With Mr Lyon was Better Together chairman Alistair Darling, former chancellor of the Exchequer, who stressed that if Scotland voted for independence there would be no going back.

He outlined well-rehearsed concerns over pensions, defence and whether the UK would allow an independent Scotland to use sterling as its currency.

Show results:

(Champions (C), Reserves (R))

Dairy cattle

Interbreed (C) Mark Logan, Clandeboye Estate, Bangor, Co. Down; (R) Robin and James Barr.

Red and White (C) G&G Templeton; Ayrshire (C) Robin and James Barr; Holstein (C) Brian Yates; Jersey (R) Miss Alison Hunter; Dairy Shorthorn (C) Stephen Girvan.

Sheep

Zwartbles (C) Mr A J Thorburn; (R)Jim Mair.

Charollais (C) & (R) Messrs G&B Ingram.

Beltex (C) Richard T Wood; (R) Mary Dunlop.

Scotch Mule (C) W&D Kerr & Son; (R) D M Bryson.

British Rouge (C) Mrs Patricia Imlah.

Shetland (C) Patrick Playfair; (R) Mrs J Brunton.

Bleu du Maine (C) Mrs Sally Shore; (R) William Baillie.

Hampshire Down (C) Charles Horrell; (R) E J Cresswell.

Market report

CRAIG Wilson sold 80 store bullocks at Ayr on Thursday to a top of 262.2p per kg and an average of 230.1p, while 52 store heifers peaked at 243p and levelled at 218.5p.

The Cumberland & Dumfriesshire Farmers; Mart sold 1696 prime lambs in Longtown on Thursday to a top of £128.50 per head and 296p per kg to average 241.9p (+16.1p on the week), while an unusually large show of 2656 prime hoggs peaked at £109 and 225p to level at 174.4p (+5.2p).

The 3110 cast sheep forward saw heavy ewes sell to £115.50 for Texels and average £72.95 (+28p), while light ewes peaked at £69.50 for Blackfaces and levelled at £45.77 (+£4.11). Rams sold to £156.50 for a Leicester and averaged £79.84 (-56p).