British executives prefer to play golf rather than fulfilling their "duty" as exporters, International Trade Secretary Liam Fox has suggested in an extraordinary attack on the country's "lazy" business culture.
The Cabinet minister suggested the UK had lost its way as a trading nation and had grown "too fat" on the successes of previous generations.
As the country adapts to new circumstances following the vote to leave the European Union, Dr Fox said Britain's business attitudes have to adapt.
He said: "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."
In unguarded comments at a drinks reception on Thursday night, reported by The Times, Dr Fox 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.
"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?"
He told supporters of the Conservative Way Forward group: "If you want to share in the prosperity of our country, you have a duty to contribute to the prosperity of our country."
Dr Fox also risked inflaming tensions between his department, created by Theresa May when she entered Number 10, and Boris Johnson's Foreign Office.
In his speech to Tory activists, Dr Fox dismissed the "Foreign Office view of the world" for focusing on capital cities and diplomacy rather than commerce, the newspaper reported.
He said his department would "look at the GDP map of the world" - noting that the city of Los Angeles has higher gross domestic product than Saudi Arabia.
"We have to start to think about (the world) in a totally different way," he told the reception.
"We've got to change from the cartographer's view of the world to the mercantilist view of the world. The structures of government (have) to respond to where the opportunities arise and the size of markets."
The prominent Brexit-backer suggested the UK would secure a "unique" settlement after leaving the EU.
"We are building something unique and we are going to design ways of doing business in the world which are totally different from anything that the current restrictions allow us to do," he said.
Dr Fox also revealed that investment policy would change to give equal weight to British firms putting money into overseas projects rather than encouraging the flow of foreign cash into the UK.
"Up until the change of government, the policy was to get as much foreign direct investment into the United Kingdom as possible, but to largely ignore overseas direct investment elsewhere.
"And that's a problem because it's great the year we get the foreign investment and we get jobs created, but every year after that all their income flows that go to their parent companies or their parent countries are outward flows in our current account.
"Unless we have counterbalancing overseas development, overseas investment, we are unable to get those income flows to counterbalance that."
He also appeared to rule out protectionist measures for domestic industries such as steel.
"Protectionism has always ended in tears," he said. "We must be unreconstructed, unapologetic free traders."
Former minister Pat McFadden, a senior Labour supporter of the Open Britain campaign, said: "It is hard to see why the Government's trade minister is attacking British business when he is supposed to be promoting the UK as a great place to do business."