Suzanne Plunkett / Reuters
The comments, which were first reported by The Times, were made during an event for the Thatcherite Conservative party group Conservative Way in the House of Commons on Thursday evening.
Fox also reportedly said that many executives and business people might achieve more success if they didn't always "play golf on a Friday afternoon."
Fox, a former Defence Secretary, is one of the key figures in Theresa May's first government, and is tasked with spearheading the
During the referendum, Fox was one of the most prominent Conservative Leave campaigners, although he did take a back seat to the likes of Boris Johnson and Michael Gove.
Speaking at the right-wing Conservative event, Fox reportedly said:
"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.
"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 - we've got to be saying to them if you want to share in the prosperity of our country you have a duty to contribute to the prosperity of our country."
"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?"
According to Oliver Wright and Henry Zeffman at The Times, Fox "also warned industry that his department was unlikely to protect any sector of the economy with import tariffs and was prepared to see them sink or swim in the post-Brexit world."
Fox is a well-known advocate of a so-called 'hard' Brexit, whereby Britain leaves the European Single Market completely, and does not subscribe to a Norwegian or Swiss model of association with the EU, but instead, negotiates individual deals on trade.
A spokesman for Dr Fox told The Times that he was "committed to supporting the full range of businesses in the UK so that they can take best advantage of the opportunities that Brexit represents."
A Downing Street spokesman said Fox expressed his own personal views during the event, and not those of the government, a BBC report notes.