Zia Yusuf, who resigned as Reform UK chairman on Thursday, is to return to work for the party in a new role.
Yusuf will lead what the party calls its "Doge team" – which is modelled on the Department of Government Efficiency set up by US President Donald Trump.
Earlier this week, Yusuf quit the party, saying working to get the party elected was no longer "a good use of my time", without expanding further.
On Saturday, Reform UK leader Nigel Farage told the BBC that Yusuf will take on a more public role for the party in a new role, appearing more frequently in the media.
He said: "Zia regrets what he said and did the other day. It was a combination of 11 months hard work and exhaustion."
In a post on X, Yusuf said he had received a large number of messages urging him to reconsider leaving the party and explained why he quit two days ago.
"After 11 months of working as a volunteer to build a political party from scratch, with barely a single day off, my tweet was a decision born of exhaustion," he wrote.
Yusuf said he came into politics "out of belief that Nigel Farage was the man" to lead the country, adding "I believe in these things more than ever".
Before his resignation, Yusuf had criticised Sarah Pochin, who won last month's Runcorn and Helsby by-election for the party.
She urged Sir Keir Starmer to ban the burka "in the interests of public safety" during Prime Minister's Questions debut on Wednesday.
Yusuf said it was "dumb for a party to ask the PM if they would do something the party itself wouldn't do".
This breaking news story is being updated and more details will be published shortly. Please refresh the page for the fullest version.
You can receive Breaking News on a smartphone or tablet via the BBC News App. You can also follow @BBCBreaking on X to get the latest alerts.