The co-option of a parish councillor occurs in two instances:
When an ordinary vacancy has arisen on the parish council after the ordinary elections held every four years, or when a casual vacancy has arisen on the parish council and no poll (by-election) has been called.
A casual vacancy occurs when:
- A councillor fails to make his declaration of acceptance of office at the proper time;
- A councillor resigns;
- A councillor dies;
- A councillor becomes disqualified, or;
- A councillor fails for six months to attend meetings of a council or committee.
The parish council must notify the borough/district council of a casual vacancy and then advertise the vacancy and give electors for the ward the opportunity to request an election. This occurs when ten electors write to the borough/district stating that an election is requested.
If a by-election is called, a polling station will be set up and the people of the ward will be asked to go to the polls to vote for the candidate who will have put themselves forward by way of a nomination paper. The parish council will pay the costs of the election. The people of the ward have fourteen days (not including weekends, bank holidays and other notable days), to claim the by-election.
If more than one candidate is then nominated a by-election takes place but if only one candidate is put forward, they are duly elected without a ballot. If ten residents so not request a ballot within fourteen days of the vacancy being posted, the parish council is able to co-opt a parish councillor.
On confirmation from the Electoral Office that no by-election has been claimed, the casual vacancy can be filled by the means of co-option and the clerk then advertises the vacancy for a period agreed by the council on noticeboards and website.