Nigel Farage says Reform UK has “grown up” as he concluded a “joyous” conference with members' backing for new party rules – while grassroots activists dismissed concerns he was seeking to consolidate his power.

Nigel Farage today claimed Reform UK had “grown up” as he concluded a “joyous” party conference in Birmingham.

The 60-year-old admitted he was “a little hoarse” after a boozy party last night as he delivered his closing speech at the two-day gathering.

Mr Farage told 4,000 activists gathered at the National Exhibition Centre: “You are in control” after deciding to give up ownership of the party.

He used the party congress to promise a “professionalization and democratization” of the reforms and received a boost today when members overwhelmingly approved a new party constitution.

The 17-page document gives Mr Farage, as party leader, significant powers to appoint board members and key officials.

It also sets out the hurdle that must be cleared before Mr Farage faces a motion of no confidence if MPs or party members seek his removal.

But grassroots activists dismissed fears that the former UKIP leader would have an even tighter grip on his new party despite giving up his ownership rights.

The reform leader had previously appeared on the conference's main stage to officially sign a copy of the party's new constitution.

A reform activist wearing a Union Jack T-shirt with the words “Fearless” on it attends the second day of the party conference at the National Exhibition Centre

One party member said chairman Zia Yusuf could one day replace Mr Farage as party leader.

In his final address to the Reform Conference, Farage praised “the most joyous gathering of a political party that I believe has ever taken place in the modern history of this country”.

He had previously appeared on the conference's main stage to officially sign a copy of the party's new constitution, which, according to party leader Zia Yusuf, is focused on the members.

Mr Yusuf welcomed the official adoption of the document by a vote in the conference hall as “an important and historic day for this party”.

Reform activists, who had greeted Farage's arrival at party conferences with cries of “Nigel, Nigel, Nigel”, were reluctant to criticise the party's newly adopted rules.

Mark Fox, the Reform Party candidate in the Kingston and Surbiton general election, did not vote for the constitution, but said this was only because of “some minor quirks” in the wording.

He told MailOnline: “In all parts it's a pretty solid document. There are just parts where I wish we'd had a bit more time to discuss and refine.”

“There can be no pure democracy in a political party… There needs to be leadership, guidance, control, and difficult decisions have to be made.”

While Fox acknowledged that the new party rules could cause “long-term” problems, he rejected suggestions that the document represented a power struggle by Farage.

“No, not at all. The irony is that when Nigel was in UKIP he had real problems with the national executive committee, so I'm surprised he did that,” he added.

“In many ways he has accepted that such a system must be in place.”

Martin Belt, a party member from Bridlington and The Wolds, described the document as “fabulous”.

And Thomas Joynson, a Reform Party member for Chester South and Eddisbury, supported Farage's right to maintain a firm grip on the party.

“He created the reform, so he should be allowed to decide what to do with it,” he said.

“He should have the power to appoint the board because if something goes wrong he will be held accountable.”

Mr Joynson said he had been a lifelong Conservative voter but supported Reform in the July election and joined the party shortly afterwards.

Martyn Sutton, from the Lancaster and Wyre Reform branch, said party members would “find their feet” as the party grew over the coming years.

He said Mr Yusuf could one day replace Mr Farage as party leader.

“Nigel won't last forever, will he? I know some people think – whatever the future holds for him – that without him there would be no Reform UK,” he said.

“But I don't necessarily think that's true. I'm really inspired by Zia Yusuf, I think he's fantastic and maybe that's where the future lies.”