Nine Hartlepool councillors have defected to the Brexit Party and agreed to form a pro-Brexit coalition with three local Tories.
The alliance is a further blow to the Labour party who lost control of all five Tees Valley councils and dozens of seats last May.
The seaside town voted overwhelming in favour of Brexit in 2016 with 69.6% backing the leave vote in the EU referendum.
Now several councillors have made the switch in the hope of helping deliver Brexit.
Brexit Party chair Richard Tice said: “Something truly admirable has happened nearby in Hartlepool.
“Hardworking local councillors have organised and put country before party so they can defend democracy from Corbyn’s Labour.
“I can reveal today that nine councillors from different parties have joined the Brexit Party and agreed to work with three Tories to secure a pro-Brexit majority for the town.”
He added: “The Brexit Party is reaching out in traditional Labour heartlands, offering a democratic alternative, and we are also ready to stand against those Tories who are aiding Corbyn’s anti-democratic alliance.”
Cllr Tom Cassidy, who has joined the Brexit Party, said: “I could no longer sit back and witness the 70% of people who voted here in 2016 being ignored by MPs in Westminster.
“Joining the Brexit Party as one united team is the only way we can stand up to the establishment and Labour Party who now back remain.”
Labour suffered humiliation in the local elections in May as it lost control of councils across its Teesside heartland.