Boris Johnson, the leading contender to become Britain's next prime minister, said on Tuesday it would be "bizarre" if the EU opted to impose tariffs on British goods in the event of a no-deal Brexit.
Johnson, vying with foreign secretary Jeremy Hunt to replace outgoing premier Theresa May, insisted her divorce deal struck with the bloc but repeatedly rejected by MPs was "basically dead".
The ex-London mayor told a radio phone-in that Britain must "get ready to come out without an agreement" and the European Union should match his plan not to impose any tariffs under such a scenario.
"It would be very bizarre if the EU should decide on their own -- we wouldn't put up tariffs -- to impose tariffs on goods coming from the UK," he told LBC talk radio.
"It wouldn't be in the interests of their businesses, let alone their consumers.
"It would be a return to Napoleon's continental system," he added, invoking the 19th-century French emperor who attempted to blockade Britain in the Napoleonic Wars.
During the radio phone-in, former foreign secretary Johnson delved further into his Brexit strategy if he were to be elected Conservative leader -- and therefore prime minister -- by party members next month.
The 55-year-old said he wants to "take the serviceable bits" of May's withdrawal agreement, while scrapping the "backstop" provision -- hated by ardent Brexiteers -- intended to keep the Irish border open.
Johnson said he would withhold paying the EU Britain's £39 billion ($50 billion) bill while the two sides negotiate a free trade agreement during an implementation period prolonging current terms.
However European leaders have vowed they will not allow London to cherry-pick only the parts of the divorce deal it likes, and that the backstop must remain in place.
If Brussels maintains that stance, Johnson said he would ask EU leaders to agree to freeze existing arrangements for up to 10 years while they negotiate their future relationship.
That could happen under a provision in World Trade Organisation (WTO) rules, but he acknowledged "there has to be agreement on both sides" for such an arrangement.
Johnson insisted a way could be found through the political impasse that has led Brexit to be delayed twice already.
"Let's be more positive about this," he said.
"It's time this country frankly stopped being so down about its ability to get this thing done."