Pedmore ward members Cllr James Clinton and Cllr Jason Thorne switched to Reform in a move announced on November 9.
The changes increase Reform’s presence on Dudley Council to three as the pair join Cllr Shaun Keasey, also a former Conservative.
Marco Longhi, former Dudley North MP and senior Reform UK campaigner, said: “This is a big moment for Reform in Dudley. James and Jason are dedicated local councillors who know their residents deserve better than the tired old parties. Their decision shows the momentum is unmistakable.
“The turquoise wave is coming, and Dudley is leading the way.”
The switch was condemned by the council leader, Cllr Patrick Harley, who removed Cllr Clinton from his cabinet in the last reshuffle after a poor performance during budget scrutiny.
Cllr Harley said: “Pedmore is probably one of the safest seats in the borough for us so why these two have decided to do what they have done is beyond me.
“They have let down a lot of their friends – we are a family in the Conservative party.
“The decent thing would be for them to have two by-elections but I don’t think either one has got the courage to do that.”
The next scheduled council elections are in May 2026 when Cllr Thorne’s seat will be up for grabs.
Cllr Harley said: “I look forward to ensuring next May Jason Thorne loses his seat wherever he decides to stand, they have shown no loyalty or integrity and they deserve everything they are going to get when the electorate makes their decision.”
The elections in May could see Reform gaining a sizeable chunk of council seats but Cllr Harley questioned what voters will be getting from the party in Dudley.
Cllr Keasey was last elected as an independent having left the Conservative Party while Mr Longhi represented Dudley in Westminster as a Tory.
Cllr Harley said: “Longhi can hardly say this is the change people need – you have got the same old faces.
“It’s people who have failed as Conservatives.”