Gordon McKie, the chief executive of the Scottish Rugby Union, yesterday issued a trenchant attack on Bob Carruthers, the co-owner of Edinburgh, as the row between the two parties reached a critical point with the governing body's decision to order the club to leave Murrayfield and repay £1.4m in advance funding by the end of normal business today.

Until now McKie has been reluctant to speak publicly about the conflict, but, following a unanimous vote of confidence in his handling of the issue from the SRU's Board and Council, he launched a withering critique of the manner in which he believes Carruthers has damaged the sport's reputation. This, he says, includes systematically leaking confidentiality agreements, regularly moving the goalposts in his discussions with the SRU, undermining morale at Edinburgh by disaffecting players, and failing to invest to the extent he promised he would when he became involved with Edinburgh last summer.

"Edinburgh terminated their operating agreement with the SRU, and the effect of that is the money we have given them in the past 12 months is repayable," said McKie. "We have also asked Edinburgh when they are going to leave Murrayfield and we also need to find out where they plan to go, given they have commitments in the Magners League and Heineken Cup, and they can't simply play anywhere.

"Bob Carruthers terminated the agreement, and we were very surprised he did that. Although I am aware he has been making fresh allegations about us elsewhere, I want to make certain things clear to the people who really matter, namely the players and supporters of Scottish rugby.

"Firstly, we have stuck to the contract we signed with Bob Carruthers 100%; it was a sensible commercial deal at the time, and we have subsequently tried to help him and his club, but we simply could not reach any agreement. Mediation would be pointless; that only works when you are dealing with professional individuals who understand the concept of confidentiality.

"While we remain absolutely committed to having two credible professional sides in Scotland, there is no value in dealing with somebody who has talked about turning Edinburgh into Stirling Albion - his words - and who has spoken about moving his players to the Cayman Islands, when he has no power to do any such thing. If he pays the £1.4m by close of business on August 3, then we will have to look at his plans to run a professional team; if he doesn't, then, as creditors, we will assess the situation.

"The SRU is determined that this situation must end quickly, because it is damaging the credibility of Scottish rugby and we can't allow that to continue just a month before we go into the World Cup campaign."

Carruthers, who seemed surprised by the union's move on to the offensive, sought to respond with a number of counter-arguments, but McKie, who perhaps should have reacted in this manner when the spat initially erupted more than three weeks ago, issued a point-by-point repudiation of these assertions to The Herald last night.

Carruthers: "There's no such thing as an operating agreement with the SRU.

There is a facilities agreement, whereby the SRU were due to pay monies to Edinburgh. They failed to pay the monies and, therefore, we have rescinded the contract."

McKie: "We have a number of agreements with Edinburgh, and he terminated more than one of these, not at our behest. We were taken aback when he did it, only because he should have realised it provided us with the chance to reclaim monies from him. The SRU has examined the contract which we signed with the original Edinburgh board and we are very comfortable with our position. We don't want to enter into litigation but, if we have to, then we will defend ourselves vigourously."

Carruthers: "The total amount of the facilities over the five years was £8m, and that would have to be shown in the SRU accounts."

McKie: "That's just complete nonsense. Our accounts have been audited by PricewaterhouseCooper and have been witnessed by the SRU Board. Since we entered into the partnership, we have handed over £2m to Edinburgh. It costs around £2.5m a year to fully fund a pro team, so you can do the arithmetic on how much of the money has come from elsewhere?

"Where is the £2.5m which Carruthers offered publicly to help save the Border Reivers? And does he deny that his investment in Edinburgh has been less than £0.5m?

Carruthers: "They are trying to engineer a dispute, so they can ask for the money back, but you can't just bully people and behave like this."

McKie: "It was Edinburgh who resigned from the SRU to start the whole argument. It is they who terminated the operations agreement this week. We have done our best to keep this in-house and reach some kind of agreement, but Carruthers has issued all manner of contradictory claims and counter-claims. Why doesn't he admit that his concert business has failed to live up to expectations? Because that is the truth of the matter and explains why he is asking for money which we do not owe him."

As news of the SRU's action spread yesterday, the Scottish sports minister, Stewart Maxwell, urged the SRU and Edinburgh to resolve their differences, but confessed that he was powerless to intervene.

"I think most people would be disappointed by the fact that this dispute is ongoing," he said, "but it is a private matter, a contractual dispute between the SRU and Edinburgh. I am just keen they resolve it sooner rather than later."

You suspect that, if Carruthers does not find the £1.4m by 5pm tonight, he will be forced to admit defeat.