In the ruling issued on Monday, Justice Helen Wasilwa said Adul is legally in office and can only be ousted if proper procedure was followed.
“The Speaker was unlawfully removed and the court has quashed the proceedings of the assembly of 16 October 2014 and 21 October 2014 because the procedure used was not right,” she said.
Wasilwa further ruled that the person purporting to act as the Speaker did not have the capacity under law to do so and Adul must resume work.
The Judge faulted the procedure used in impeaching the Speaker late last year when MCAs accused her of failing to discharge her mandate properly.
She said the assembly has the right to start a fresh process to impeach the Speaker.
The assembly impeached Adul late October last year when 39 MCAs voted to have her impeached.
Adul later moved to court challenging her impeachment terming it illegal.