Chief executive Paul Walsh told US analysts the closures, which will save the drinks giant £42 million a year, were “the right thing to do” after going on BBC Scotland to say he was open-minded about a government scheme to avoid the shutdowns.

MSPs, who will debate the Diageo closures at Holyrood on Wednesday, said Walsh was guilty of “shocking” behaviour. The revelation will put further strain on relations between the government and Diageo, which currently employs 4500 people in Scotland.

Diageo last night said it was “categorically untrue” that Walsh had made up his mind in advance, and blamed an “issue of phrasing” for any impression to the contrary.

The row follows Diageo’s confirmation on Wednesday that it is to shut its Kilmarnock and Port Dundas, Glasgow, operations with the loss of 900 jobs, while creating 400 new posts in Fife. Kilmarnock has been home to the firm’s Johnnie Walker whisky for 190 years and Diageo is the town’s biggest private employer.

The closures followed weeks of negotiations between the company, councillors, the SNP government and Scottish Enterprise about alternatives, such as scaling down the Kilmarnock bottling plant and relocating it to a smaller site. Diageo flatly rejected the idea, saying it did not address the “basic economics” of its business.

David Gosnall, managing director of global supply at Diageo, insisted the government’s proposals, set out by finance secretary John Swinney on September 3, had been “examined thoroughly”. However, the Sunday Herald can reveal that on August 27, the day Diageo announced global

pre-tax profits of £2 billion, Walsh gave a rather different impression.

In the morning, he told BBC Scotland: “I will be very open-minded when I look at the content [of the government plans]... I hope the content is specific and provides options that still maintain our business objectives, ie, being cost-competitive.”

Then, in an afternoon conference call with US investment analysts, he said Diageo had “firmly grasped the nettle” of restructuring “as we close plants in Scotland”. In a transcript published on Diageo’s website, Walsh said: “Bear in mind that a lot of the restructuring efforts that we’ve announced over time will help gross margin. Equally I will be the first to say that some of these programmes are challenging. They may invoke some letters to our shareholders, as we close plants in Scotland.

“But it’s the right thing to do for the future, and we have firmly grasped that nettle in order that we do not see gross margin slippage.”

Willie Coffey, the SNP MSP for Kilmarnock, said the “shocking” conference call reinforced his fear that Diageo had never been serious about trying to avoid closure. “They gave a firm commitment to examine the [alternative] plan, but the first we heard back was when they told the cabinet secretary there was no deal,” he said. “I suspect they were just paying lip service to the hopes of an awful lot of people in Kilmarnock. I don’t believe we have been dealing with honourable people here.”

Douglas Reid, SNP leader of East Ayrshire Council, also said Walsh’s comments were “shocking”, especially as he and other campaigners had handed a letter in to the company’s London HQ the same day, and been assured negotiations were ongoing.

“It confirms my impression that Paul Walsh is this kind of alpha male whizzkid in braces from the 1980s, who can’t be seen to be wrong ... It’s capitalism at its worst.”

A Diageo spokeswoman said: “From the announcement of our proposals in July, Diageo has been both transparent and consistent in our approach to alternative business proposals.

“At the time of these comments no credible alternative proposal for Kilmarnock and Port Dundas was on the table. That is still the case.

“All proposals received were given the fullest of consideration but were rejected because they did not meet Diageo’s requirements for the future sustainability of the business in Scotland.”