Speaking on Sky News Mr Farage said: “I’ve no idea where he stands on the third runway, I’ve no idea where he stands on HS2, I’ve no idea where he stands on sugar taxes.
“Immigration. In fact this is a guy that just flips and flops, says what he thinks the audience wants to hear.
“An when it comes to Brexit, I heard him yesterday talking in Belfast saying that the Irish Backstop was unacceptable and yet he voted for it.”
In the same interview Mr Farage confessed to not “trusting anything that the Conservatives say at this moment in time”.
Speaking on Good Morning Britain, Mr Farage said neither Mr Johnson or Jeremy Hunt “have the guts to deliver Brexit”.
Mr Johnson has vowed that Britain will leave the EU on October 31 with or without a deal and Mr Hunt has said he would give the EU three weeks to renegotiate the withdrawal agreement.
Read More on Yahoo News:
At a leadership hustings last week, Mr Johnson has insisted he would not work with Mr Farage in Brexit talks.
Rory Stewart, who came fifth in the Tory leadership contest, said during his campaign that he would work with Mr Farage to solve the Brexit issue.
The Brexit Party MEPs turned their backs on the EU’s national anthem yesterday in Strasbourg.
The European parliament’s president, Antonio Tajani, criticised the action saying: “It is a question of respect; it doesn’t mean that you necessarily share the views of the European Union. If you listen to the anthem of another country you rise to your feet.”