The former Ukip leader attacked what he called the “deeply worrying” failure of exit talks to address border controls after a meeting with Michel Barnier.
Mr Farage said Mr Barnier does not understand at all that concern over immigration fuelled the vote to leave, but instead believes the result was down to the promise of extra cash for the NHS.
In a meeting in Brussels, the divisive politician also warned that businesses will push for the Government to walk away from talks if the EU fails to make any concessions on financial services.
He told Sky News: “What he [Barnier] really didn’t understand at all was that open-door immigration within the European Union had been an absolute key driver of all of this.
“He really doesn’t see that. The most disappointing thing, if I am speaking on behalf of the 17.4 million, most of them anyway, is that it’s pretty clear that in the talks that have happened so far immigration, frankly, hasn’t even been discussed.
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“We haven’t even begun to talk about how we are going to put some proper controls in place.”
Mr Farage said it was clear that the Government has not yet discussed border controls with Mr Barnier, which is “deeply worrying for Brexiteers”.
The MEP told Mr Barnier that if the EU was prepared to offer a tariff free deal on goods but was not cooperative on services “he might be in for a surprise”.
Brussels will find a growing number of British businesses may decide “it’s best we just leave” under World Trade Organisation rules if the UK is treated badly, he said.
The former Ukip leader warned that it would be pointless to spend years negotiating to get a deal on services that he did not think Mr Barnier “wants to give us”.
He said it is time for the EU to “give a bit back” on services but while Mr Barnier was “polite”, his body language indicated that he does not want to “give too much on that”.
Mr Barnier is expected to hold meetings with other prominent leave supporters in the coming days.
Mr Farage said: “At this meeting no cameras were allowed, no photos were to be taken. I think he was as pleased to meet me as David Cameron was to hold the referendum.”
European Commission spokesman Margaritis Schinas said: “The two men discussed the state of play of the Article 50 negotiations.”