A by-election will take place in October after Councillor Colin Clark announced his resignation from Aberdeenshire Council.
Cllr Clark represents Inverurie and District Ward and has said he will step down after becoming the Gordon MP on June 8.
An Aberdeenshire Council spokesman said: “Plans are now being put in place for a by-election on October 12, with the count taking place the following day.”
Details are to be announced soon.
Cllr Clark said: “I said during the election campaign that I would step down if I was successful in becoming an MP.
“Given the demands of the job, including the requirement to be in London through the week, I do not feel that I can also commit the time required to fulfil the local councillor role.
“I will be donating all of my councillor salary from June 8 onwards to charity.”
Cllr Clark became a councillor in November at a by-election following the resignation of previous incumbent Martin Kitts-Hayes.