In that result, Labour’s Mark Cherry lost his Banbury Ruscote seat to Conservative Jayne Strangwood as candidates gathered in Banbury’s Spiceball Leisure Centre.
The county council confirmed there had been an ‘administrative error’ in the result, and it is understood Labour plans to make a legal challenge to the result.
A spokesperson for the Labour Party said: "The Labour Party will be launching a formal challenge to the declaration of the Banbury Ruscote County Council election. It has been widely accepted that an administrative error may have been made in the declaration of the result and all parties are keen to rectify this as soon as possible."
No further comment was released as the issue will now be subject to legal proceedings.
If successful it could reduce the Conservatives lead over the Lib Dems, leaving them level with 21 seats apiece on the council.
The Conservative leader of Oxfordshire County Council was among those who lost their seat in an election results day where the party saw many majorities overturned.
The council has been left with no overall majority control as a result of the election.
The Conservative group remains the largest on the council, but it now has only 22 seats, far short of the all out majority of 32 needed to claim power.
Following them were the Liberal Democrats with 21 seats, the Labour Party with 15, the Greens with three, the Henley Residents Group with one, and one seat went to independent, Les Sibley, of Bicester West.
It remains to be seen what kind of governing group will be formed.
Ian Hudspeth the leader of the council and councillor for Woodstock, was among the Conservative councillors who lost their seats, results of the poll counted yesterday revealed.
Mr Hudspeth had served as leader of the county council since 2012, having been elected in 2005.
He said: “It is very disappointing obviously, but that is democracy for you and that is what the ballot box has said.”
He also thanked his Conservative colleagues and wished good luck to those who had won in their council divisions again.
Labour meanwhile gained Chipping Norton and Witney North and East from the Conservatives.
Both of these seats had Tory councillors who had resigned from the party in the run up to the elections to sit as independents, Hilary Hibbert-Biles and Suzanne Bartington, neither of whom stood again.
The Greens also gained two extra seats from the Conservatives in Kidlington South and in Berinsfield and Garsington, as well as holding the Wallingford seat they won at a by-election in 2019.
But the Lib Dems were the party that shook up the political make-up of the council most.
As well as claiming the Woodstock seat from Mr Hudspeth, they claimed seats in other former Conservative strongholds in Eynham, Thame and Chinnor, and Otmoor, while holding onto marginals like Sutton Courtenay and Marcham.
Oxford Lib Dem MP, Layla Moran, who took part in canvassing, said her party had experienced ‘sensational results’.
The election count took place at four different venues across Oxfordshire, whereas it would usually take place in just one.
Venues included Banbury’s Spiceball Leisure Centre, Oxford Town Hall, the White Horse Leisure Centre in Abingdon, and the Windrush Leisure Centre in Witney.
In the primary count centre at the Spiceball Leisure Centre, the mood among candidates was quiet and tense as they awaited results, but there was also civil and often friendly discussion across party lines.