Nigel Farage accused the Tories of copying the rhetoric of Reform UK, “but not the actions”, as he opened a party conference centred on Brexit and immigration.
The former Ukip leader said the Conservatives have become a “social democrat party in all but name” with “big-state, high-tax” policies.
Both Mr Farage and Reform UK leader Richard Tice have sought to paint the party as an alternative for those on the Tory right who voted Leave in the 2016 referendum.
Their attack on Government centres on what they claim amounts to a failure to properly deliver Brexit by repealing more EU-era laws and controlling immigration more tightly.
Speaking at the Reform UK conference, which carries the slogan Let’s Save Britain, Mr Farage told the PA news agency: “A lot of the arguments that we’re making, arguments on the cost of net zero, arguments on what is happening in the English Channel, for example, have been noticed, and the rhetoric was very much copied by the Conservatives over the course of the last couple of weeks, but not the actions.”
Reform UK, previously named the Brexit Party and headed by Mr Farage, has never had any MPs.
It also had a poor showing in the May local elections, failing to gain any seats despite fielding nearly 500 candidates and losing half its councillors, retaining eight.
But the party has consistently been in fourth place in opinion polls at around 6%, just ahead of the Green Party.
It has returned the word “Brexit” to its party logo for its 2023 conference, saying it intends to reclaim the word from the Conservatives in the run-up to a general election expected next year.
In his speech to party conference, Mr Tice sought to appeal to opponents of climate policy and open borders by saying Reform UK wanted to go “net zero” on immigration rather than carbon emissions.
Appearing to refer to people who arrive in the UK having crossed the Channel, he said: “Let’s pick up, let’s take back to France, and then show the EU leaders this is what they need to do in the Mediterranean.
“Only then will this crisis, this hurricane of migration that Suella Braverman talked about, only then will it be stopped.”
Mr Tice was alluding to the Home Secretary’s controversial speech at Tory Party conference in which she said a “hurricane” of mass migration is coming, causing unease among some senior Conservatives.
The four-day event in Manchester included a surprise appearance from Mr Farage, during which he snubbed Prime Minister Rishi Sunak’s open door policy on a return to the party but gleefully posed with a steady stream of Tory members.
“Maybe he thought… that I could be tempted to re-join a party that has betrayed many of those Brexit promises,” he said to loud applause in a speech at the Reform UK conference.
“It’s very, very sweet of you Prime Minister but I’m really sorry, the answer is no, I will not.”
He said he would focus his efforts on backing Reform UK, saying there was a “gap in the political market” for the party to fill.
Likening its position to that of Ukip in 2012, Mr Farage said: “This party has been bubbling away quietly just under the radar.”
Reform UK plans to field 630 candidates across England, Scotland and Wales in the next general election.
It has ruled out standing aside to allow the Conservatives to gain more seats, as it did in more than 300 seats under its Brexit Party name in 2019 to avoid splitting the Leave vote.