Four councillors on Portsmouth City Council have switched from an independent group to Reform UK.
Derek North, Russell Simpson, Matthew Cordy, and Chris Dike were members of the Portsmouth Independent Party but announced they were moving to Reform UK.
It means Reform UK now has six councillors on the council which is currently run as a minority administration by the Liberal Democrats.
Mr Dike said the party was a “genuine opportunity to deliver change locally and nationally”.
“We’re proud of what we’ve achieved as independents, but we’re even more excited about what we can now achieve as part of a growing national movement,” he added.
It leaves Reform UK as the third biggest party on the council – behind the Lib Dems and Labour.