Trade secretary Liam Fox been widely criticised after accusing British businesses of growing "too lazy and too fat" and claiming executives prefer to "play golf on a Friday afternoon" than export products overseas.
The unguarded comments were made at a drinks reception for the Conservative Way Forward group and were reported by The Times, which obtained a recording.
Politicians from across the parties criticized Mr Fox, whose remit is to position the UK as a global player following the decision to leave the EU,
Number 10 also distanced itself from the remarks, with a source saying the trade minister was expressing his "private views".
- Video report by ITV News political correspondent Libby Wiener
Vince Cable, the former Liberal Democrat business secretary, condemned the comments as a "sort of crass, lazy generalistion".
"I suspect most businesses are much less worried about their golf handicap than they are the handicap of trading under all the massive uncertainty now around Brexit," he added.
Shadow business secretary Jon Trickett said: "British firms are not 'fat and lazy' as Liam Fox suggests; they are suffering from a government that has no idea how to build an industrial strategy."
Former Labour shadow business secretary Chuka Umunna also said Mr Fox's comments were a "complete disgrace" and he should apologise in a series of tweets.
Mr Fox reportedly told Conservative supporters: "This country is not the free-trading nation that it once was. We have become too lazy, and too fat on our successes in previous generations."
"What is the point of us reshaping global trade, what is the point of us going out and looking for new markets for the United Kingdom, if we don't have the exporters to fill those markets?"
The minister, who was a medical doctor before he went into politics, reportedly added: "We've got to change the culture in our country.
"People have got to stop thinking about exporting as an opportunity and start thinking about it as a duty - companies who could be contributing to our national prosperity but choose not to because it might be too difficult or too time-consuming or because they can't play golf on a Friday afternoon."
Dr Fox's comments are unlikely to be popular with business executives.
He also appeared to risk tensions with his colleague Boris Johnson, the foreign secretary, after he dismissed the "Foreign Office view of the world" for focusing on capital cities and diplomacy rather than commerce, the Times reported.
A spokesman for Dr Fox said the minister was "committed to supporting the full range of businesses in the UK so that they can best take advantage of the opportunities that Brexit presents".
A statement from the Labour party called Dr Fox's comments "offensive and crass".
The statement quoted Jonathan Ashworth, shadow minister without portfolio, as saying: "Every MP knows of hard working businesses in their constituency who are struggling at the moment. None of them are lazy or more interested in playing golf."