British exporters would face total tariffs of around £5.2 billion, but tariffs on European Union imports would raise a much larger £12.9 billion, and they could be compensated through a combination of research grants, subsidies, and general tax cuts.
"At the beginning [of the negotiations] you'll remember we had a slightly hard month of two where there were talks of punishment and Lord knows what else", Mr Davis told the European Union Select Committee.
She said: "It is slightly baffling, as it is the Prime Minister, or at least the Prime Minister for now, who made a decision to put the no deal option on the table and she couldn't stop using the phrase during the election campaign".
As has been frequently mentioned over the past year, the United Kingdom voted on June 23rd, 2016 to leave the EU. Mr. Barnier said Britain must offer more clarity on its position on the "divorce bill" financial settlement with the European Union - as well as the status of expat citizens and the nature of the future border with the Republic of Ireland - if it is to make progress towards a deal on trade arrangements after Brexit.
Britain wants to regulate citizens' rights under British law - the issue was a pet peeve of Theresa May's for years during her time as interior minister - but Barnier said if Britain opposed this "it would create uncertainty".
He said: 'The EU positions are clear.
Barnier said the European Court of Justice (ECJ) must have jurisdiction to guarantee citizen's rights, one of the EU's main conditions.
"The three priorities for the first phase are indivisible", said Barnier, referring to the financial settlement, citizens' rights and other separation issues such as the Northern Irish border.
The EU had made its stance on the issues clear, Barnier stressed, adding that it was waiting on Britain to do the same. "I'm ready. I'm very prepared and willing to work on this very quickly - night and day, the weekend", the EU Brexit negotiator said.
"I can't see how we win the hearts and minds of those who voted for Brexit by telling them that we should now enter into a new arrangement which, in exchange for a large fee, will allow the European Union to make all the rules for us because we gave up our European Union seat and ability to shape things".
London and Brussels have to agree on the terms for calculating the bill but early estimates have indicated that this could be between 60 billion euros ($68.92 billion) and 100 billion euros ($114 billion).
"I think "go whistle" is an entirely appropriate expression", he told lawmakers in the House of Commons.
The EU's chief negotiator today hit back at Boris Johnson's jibe that Brussels can "go whistle" for its massive Brexit divorce bill as tensions flare over negotiations.
He said there was no way the two sides could strike a fruitful relationship in the future if Brussels could not trust Britain to honour its commitments and implored ministers to reconsider.
He will also hold talks with Labour leader Jeremy Corbyn and Carwyn Jones, the Welsh first minister.
"We have to negotiate intelligently and sensibly, but above all negotiate with respect and expect to be respected in return", he added, dismissing Johnson's comments as "arrogant".