On Monday he said the earlier-than-expected election had come too soon for his Reform UK party but called on supporters of Sunak's Conservatives to "join the revolt" and pitched Reform as the only ones who could hold to account Labour, whose leader Keir Starmer is forecast to become the next prime minister.
Farage is one of Britain's most recognisable and divisive politicians and has pressured successive governments into more aggressive stances on cutting immigration. He played a pivotal role in the 2016 vote to leave the European Union.
But his career has been spent campaigning from the sidelines of British politics, having stood unsuccessfully for a seat in parliament seven times and led parties which, despite attracting millions of votes, have failed to weaken the grip of Britain's two main parties - the Conservatives and Labour.
This time Farage is standing in Clacton-on-Sea, southeast England, where polling shows he could win a place in parliament, but under Britain's electoral system Reform is only expected to win, at most, a handful of seats across the country.
"We are not pretending that we are going to win this general election," Farage said at the launch of a 24-page policy document, which he described as a "contract" with voters for the next five years.
But he added: "Our aim and our ambition is to establish a bridgehead in parliament and to become a real opposition to a Labour government."
Reform chose Merthyr Tydfil for its launch to highlight what it says is Labour misrule in Wales.
Farage's unexpected entry into the election race - having initially said he would not run and wanted to concentrate on campaigning for Donald Trump in the United States - has split support among Britain's right-of-centre voters.
The Labour Party is around 20 percentage points ahead in opinion polls and forecast to win a large majority. Reform overtook the Conservatives in one poll last week, and Farage has set a target of winning six million votes at the July 4 election.
Other polls put them far behind the governing party.
"JOIN THE REVOLT"
The Reform campaign has so far focused on Farage and his populist appeal.
The 60-year-old received an expensive private education and worked as a commodities trader but has successfully styled himself as a man of the people taking on an out-of-touch political establishment.
Reform's policies are designed to appeal to the right of centre voters who would typically back Sunak's Conservatives, and they demand change across all the main policy areas.
Immigration, the issue on which Farage has for more than a decade struck a chord with voters, received top billing.
Reform promised to immediately freeze "non-essential" immigration, leave the European Convention on Human Rights, and push migrants arriving by small boats back to France before they land on British shores. They also proposed an extra payroll tax on companies who employ foreign workers.
That tax was one of a raft of measures, including shaving 15 billion pounds off the benefits bill, to raise money that would be spent on tax cuts elsewhere, including raising the income tax threshold to 20,000 pounds, slashing fuel duty by 20 pence per litre and getting rid of value added tax on energy bills.
"This is not a protest document, this is not a protest vote," Farage said. "We're unashamedly radical, we want change, this isn't working."
