Nigel Farage has predicted he can win the next general election at a packed Reform UK conference that announced a new structure for the party but also leaned heavily into hard-right tropes and occasional conspiracy theories.

“We can win the next general election just with the numbers of people that agree with our principles,” Farage told cheering supporters in Birmingham.

“What we have to do is to be credible. What we have to do is be on the ground everywhere. What we have to do is to show that we can bring success after success after success. If we do those things, we genuinely can.”

At the gathering – which included repeated attacks on immigration, diversity and green policies, and calls to “put British people first” – Farage promised to professionalise the party and end its status as a company majority-owned by him.

Instead, he said, it would become a mass-owned non-profit organisation with “significant” control by members – although he did not set out what this would entail.

The first proper conference for the successor to the Brexit party, which won the third-biggest vote share in July’s general election, attracted about 4,000 people to the National Exhibition Centre (NEC).

With the second day of the event, Saturday, aimed at helping to organise new branches, Friday was devoted almost entirely to speeches from the main conference arena, with Farage completing a lineup of all five Reform MPs elected on 4 July.

A sequence of the speeches took on a populist and hard-right tone, with some echoing far-right conspiracies. Policies set out included the mass deportation of all overseas nationals in UK jails, an end to foreign aid, and the scrapping of diversity-related jobs in the public sector.

While Farage launched attacks on Labour and the Conservatives and echoed attacks on government “sleaze” – including by brandishing a pair of glasses – much of his address was aimed at rallying Reform members to join the professionalisation process and campaign in the local elections across England next May.

Farage, who walked on to the stage to the song Without Me by Eminem, said the aim was to win “hundreds and hundreds and hundreds” of councillors, as a bridgehead for future general election success, saying this would be modelled on the Liberal Democrats.

“I genuinely believe we can change the future of politics,” he said. “We can change the future of our country.”

In earlier speeches, Rupert Lowe, the Great Yarmouth MP, attacked organisations including the UN, World Economic Forum and “Bilderbergers”, whom he said were trying to subvert the UK.

He condemned government actions, including “inflicting an experimental jab on millions of people” during the Covid pandemic, and said the Equalities Act had allowed minorities to “impose their will and views on the majority”.

Another Reform MP, Lee Anderson, reiterated some of the comments about Sadiq Khan, the London mayor, which caused him to lose the Conservative whip, saying of Khan: “In my opinion he has given our capital city away and he should be thoroughly ashamed of it.”

Anderson also ripped up a letter telling him to pay his TV licence fee, to cheers from the crowd.

On Friday morning, the conference loudly applauded a speech from the former soldier and reality TV star Ant Middleton, who warned that mass civil unrest was imminent because the British identity was being “eradicated”.

Middleton, who formerly appeared on Channel 4’s SAS: Who Dares Wins, also said that unnamed forces were trying to distract people from the country’s problems, so “they can control you”.

“What’s British identity? British culture. British history,” he said. “Why is that being eradicated? Why is that being trampled over?”

This process, he said, would lead to frustration, then anger and finally violence: “We are at a very important and crucial stage before it teeters into civil unrest. We’ve all seen it. I don’t need to mention what it is. We’ve all seen it.”