Mr Hannan said forecast from the World Bank paints an overly negative picture of the effects Brexit will have on the UK's GDP.
In his weekly vlog, the British MEP said: "A new study by the World Bank says that if Britain leaves the EU with no deal, and devolves to World Trade Organisation terms, our trade with the EU will fall by two per cent.
"Our total trade with the EU amounts to 12.6 per cent of our GDP. We have a large domestic economy, we’re a big home market and most of our trade is outside the EU.
Daniel Hannan said that reverting to WTO rules in case of a Brexit no deal would not be "the end"
"So we’re talking about a total, in terms of our economy, of two per cent of the 12.6 per cent. In other words, around a quarter of one per cent of GDP."
Mr Hannan said that the UK losing that amount of the GDP was not "the end of the world" and dismissed claims the UK would sign "whatever" deal the EU creates in order to avoid reverting to WTO rules.
He continued: "A quarter of one per cent of GDP is hardly the end of the world and that is if we assume a worst-case scenario.
"The idea that we are supplicants, that we are desperate, that we have no other option but to sign whatever is put in front of us is simply not compatible with the figures."
EU Brexit negotiator Michel Barnier gave the UK a two-week deadline to provide greater clarity on the financial settlement it was prepared to offer as part of the divorce deal.
But Prime Minister Theresa May could decide to ignore the deadline and present her final case during the EU leaders' summit in December.
Member states are due to decide whether Brexit Secretary David Davis has made "sufficient progress" during talks on the core separation issues.
Without a Brexit deal, the United Kingdom would automatically revert to WTO rules – a position many Brexiteers would welcome openly.
Several key figures within the Tory party, alongside economists and historians, sent Mrs May a letter urging her to adopt WTO rules immediately instead of waiting for Brussels to give the green light for trade talks.
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