The Arun Conservative group has moved quickly to elect a new leader after the recent council election.
The Tories went into the election with a massive majority but this disappeared and the Lib Dems are now the largest party at Arun District Council.
Meanwhile Conservative Gill Brown, who has led the authority since 2006, lost her Aldwick East seat to independents.
Lib Dem James Walsh is expected to become the council’s next leader on Wednesday.
Terry Chapman (East Preston) has been elected as the new Tory group leader with Mike Clayden (Angmering and Findon) remaining as deputy leader.
Cllr Chapman said: “Whilst we were disappointed at the recent results, we fully understand why this happened and are committed to holding any new administration to account.
“Our mission is to work hard for residents and represent their concerns, We have left Arun in a strong financial position and will continue to scrutinise any decisions that might threaten that.”
Arun is a council with no overall control. The Lib Dems hold 22 seats, the Conservative Party 21, Independents eight, Green Party two and Labour one.