John Lewis's boss collided with Dominic Raab the day the company reported a 99% dip in the underlying pre-tax profit.
Sir Charlie Mayfield hit the Brexit secretary after saying that companies should not consider the Brexit as a reason for bad results.
Retail profit fell from £ 1.2 million for the six months to 28 July, as the chairman blamed a challenging time for retailers & # 39; which was partially created by the Brexit & # 39 ;.
But he approached Raab directly and said that he did not say that Brexit was the reason for the reason & # 39; was for the decline in profits.
He told the BBC: "The fact is that sterling is weaker, it is more expensive to import goods … so we have to absorb that within our margin.
I'm not going to step into some thing-dong with the Secretary of State. & # 39;
John Lewis has revealed that profit before tax fell by 99 percent in the first six months of the year to just £ 1.2 million
The John Lewis Partnership, which includes the department store and the Waitrose supermarket under its brands, also said that the statutory half-yearly profit fell 80.5 percent to £ 6 million.
It warned that it still expects earnings in the new financial year & # 39; substantially lower & # 39; will be.
But against the BBC Radio 4, President Sir Charlie Mayfield said: "There is uncertainty from every direction now, but the department store is not dead. We need cool heads and will continue to focus on the customer. & # 39;
The group said the profits in the department store chain are still affected by increases in price increases not to pass consumers to higher inflation, as well as the costs of new stores and IT changes.
Sir Charlie added: & # 39; These are challenging times in the retail. & # 39;
He added: & # 39; Profit before exception is always lower and more volatile in the first half than in the second half.
It is mainly this half year, mainly driven by John Lewis & Partners, where the gross margin has been squeezed into what is the most promotional market we have seen in nearly a decade.
& # 39; With the level of uncertainty faced by consumers and the economy, partly as a result of ongoing Brexit negotiations, prognosis is particularly difficult, but we continue to expect profits for the whole year to be significantly lower than last year for the partnership as a whole. & # 39;
But his remarks were rejected by Brexit Secretary Dominic Raab.
He told the BBC: "I think there will be some temptation from companies that are not doing very well to blame Brexit and I think that's a mistake."
Chairman Sir Charlie Mayfield said that Brexit was creating uncertain times, but added: "The department store is not dead & # 39;