Mr Farage has insisted he will field candidates in every Labour-held seat despite fears such a move could hamper Tory efforts to win a majority at the general election on December 12.
He said the Conservative Party would rather risk losing the election than forming a Leave alliance with his party.
Speaking on Radio 4's Today Programme, Mr Farage said: "The job of the Brexit Party is to hold him (Boris Johnson) to account, because too many times over the last three years the Conservatives have made promises and not delivered."
On whether he was prepared to stand Brexit Party candidates down in more seats, he added: "This all started way back in September when I sent to Number 10 some polling that said that in their 40 key seats, if I endorsed their Conservative candidate, one-third of Labour voters in those seats would vote Conservative on a one-off basis to get a genuine Brexit done.
"And ever since that time, what I've realised is that the Conservatives want a Conservative majority in Parliament, not a Brexit majority in Parliament."
He added: "There are very clearly seats in which we are the lead challenger and their are other seats in which they are the lead challenger to Labour, and we could have done a deal on that basis, but the priority for the Conservative Party, they do not want the Brexit Party to get seats in Parliament.
"They'd rather risk not winning the election than having a Leave majority, a Leave alliance."
Mr Farage also said co-leader of the Leave.EU campaign Arron Banks has "given up" on the Brexit cause because he has "had enough" and got "Brexhaustion".
Responding to Mr Bank's comments that it is "time to take the chips off the table" and get behind the Conservative Party to deliver Brexit, Mr Farage said: "You're right, he (Arron Banks) has given it up.
"Look, Arron Banks has never given a penny to the Brexit Party, let's be clear about that, he's not supported the Brexit Party.
"He, I think, has just had enough of Brexit, it's Brexhaustion and he's happy, he was happy for some reason to go along with Mrs May and Boris's deal."
Mr Farage had been warned that votes for his party would hand the keys of Number 10 to Labour leader Jeremy Corbyn, with Boris Johnson insisting a Conservative government is the “only way” to get Brexit done.
The Prime Minister had stopped short of urging Mr Farage to withdraw his candidates from Tory-Labour marginal seats, but the Daily Telegraph has reported Mr Farage was offered an electoral pact that would mean the Brexit Party targeting just 40 key seats.
The newspaper said the deal was turned down by Mr Farage, who had urged the Tories to give the Brexit Party a clear run in Labour-held seats where they can "never win".
Pouring cold water over the suggestion of a pact, a Tory source said: "We don't do electoral pacts as we have been very clear on."
In a major climbdown, Mr Farage announced on Monday that his party would not run in the 317 constituencies the Conservatives won at the 2017 general election, after initially saying his party would field more than 600 candidates.
He said he made the decision amid fears that it could split the Brexit vote, leading to a hung parliament and a second referendum. But there have been calls for Mr Farage to go even further if he wants to keep Mr Corbyn out of Number 10.
Candidates who want to stand as MPs need to hand in nomination papers by 4pm, and candidates who want to withdraw their nominations also must do so but that time.
Mr Johnson said on Wednesday that the Tories were committed to a One Nation programme, despite ex-Conservative cabinet minister David Gauke - a key advocate of such a philosophy - suggesting those opposed to a no-deal "lend" their votes to the Liberal Democrats.
Baroness Brinton, president of the Lib Dems, said her party is "absolutely clear" that it is "fighting for Remain", adding: "David has not quite got to a Remain position."
She told BBC's Newsnight: "If he really wants to lend his vote to the Liberal Democrats then he could stand back in South West Hertfordshire.
"Appreciate that he doesn't want to do that, but we wish to stand in South West Hertfordshire."
Baroness Brinton added: "We will fight it for everything."
Meanwhile, the Tories are in the lead with 40 per cent while Labour is on 30 per cent ahead of next month's election, according to a new poll.
The voting intention poll for the Telegraph, which involved 2,022 adults on November 11 and 12, put the Lib Dems on 16 per cent and the Brexit Party on 7 per cent.
Elsewhere, European Council president Donald Tusk has appeared to back Mr Johnson's opponents by advising campaigners not to give up on stopping Brexit.
In a speech, Mr Tusk said: "The UK election takes place in one month. Can things still be turned around? Hannah Arendt taught that things become irreversible only when people start to think so.
"So the only words that come to my mind today are simply: Don't give up. In this match, we had added time, we are already in extra time, perhaps it will even go to penalties?
His remarks came as Ms Leadsom said she is "absolutely confident" that the Conservatives will get a free trade deal done by the end of 2020.
But when pressed on the matter on ITV's Peston, Ms Leadsom said: "Until we reach the end of 2020, we won't know for sure."
She added: "I think anybody who wants to leave the European Union with a deal needs to vote Conservative.
"Voting for the Brexit Party won't mean we leave the EU. It will simply mean we get Jeremy Corbyn."