A key council seat is up for grabs after Green councillor Keith Taylor quit his post to become an MEP for South East England.
The resulting by-election will mean the Greens and Labour will be fighting it out to win the seat which could give one of them the right to be named official opposition partyon Brighton and Hove City Council.
With Mr Taylor’s departure, the Greens have 12 seats and Labour 13. However, the Conservatives, who have 25 seats, will also be fighting hard to take the seat as it would give them decisive control of the council.
Since the election of Green councillor Alex Phillips in the Goldsmid ward, they have been vulnerable to a coalition of opposition parties.
Dubbed the Rainbow Alliance, the Greens, Labour and Liberal Democrat parties have voted together on key issues such as combatting car use and reducing housing targets at Brighton Marina.
With the election of Geoff Wells, Conservative councillor for Woodingdean, as the new mayor, the Tories also effectively lose a seat for the year as the mayor has no voting rights. This was also the case with the departing mayor, Ann Norman.
Until the by-election, Labour have been named as the official opposition party.
Mr Taylor’s departure follows his party’s triumph in the general election when party leader Caroline Lucas was elected to serve in the House of Commons for Brighton Pavilion.
Ms Lucas was a serving MEP, and under European Parliament rules, the next person on the party’s list, Mr Taylor, takes her seat without the need for a by-election.
Mr Taylor told the annual council meeting for Brighton and Hove: “I’ve spent the last 11 happy and fulfilling years as a city councillor, striving for improvements in locals’ everyday quality of life.
“Now I’m taking all I’ve learnt to Europe to try and enrich the whole south east region. I’ll work tirelessly to achieve as much as I can.
“Although I’ll be spending a great deal of time in Brussels, my home will always be here, in Brighton and Hove.
“It’s exciting to be delivering inclusive politics based on hope, around a positive vision of building a just and sustainable world. With the consistent rise in support for the Greens’ message it’s clear that’s what people want.
“I’d like to say a big thank you to my family for their support, and all our voters and residents as well as our members and volunteers.
“A special thank you and best wishes also go to Caroline Lucas as she begins her historic term as the first Green MP at Westminster.”