The Green Party has called for an investigation into alleged polling day irregularities in two closely fought divisions in Oxford in elections for Oxfordshire County Council.

The party claims hundreds of polling cards were not delivered in West Central Oxford and has asked Oxford City Council, which organised the election on behalf of the county, to investigate.

Sushila Dhall, the Green Party candidate, lost by 128 votes to Liberal Democrat Alan Armitage for the division’s second seat. Labour’s Susanna Pressel, Oxford’s last Lord Mayor, won the other seat.

In East Oxford, the Greens contacted police after claiming a voter turned up at the count to find someone had already used his vote.

Ms Dhall, who lost her seat, said: “We believe there could have been more than 600 people in streets including Southmoor Road, Kingston Road, Warnborough Road, Church Walk, and at a number of colleges who did not receive polling cards.

“You can vote without a polling card but some people are not aware of that.

“I know Susanna Pressel, who got the most votes, will shout very loudly on behalf of her constituents.

“This is not sour grapes because I lost, but I do want an investigation to find out how many people didn’t receive their polling cards.”

City council Green group leader Craig Simmons said: “We received complaints from members of the public about irregularities in the voting system in the East Oxford count and referred the matter to the police.

“We understand that a person turned up and someone had already voted for him.

“There was a recount on the night because the result was so close between second and third place but we are not challenging the number of votes cast.

“The issue at stake is whether or not the votes were cast by the right people.”

City council spokesman Fiona Collcutt said: “The deputy returning officer for the Oxford city electoral divisions has received a complaint that some poll cards were not delivered in advance of polling day, last Thursday.

“Arrangements were in place to deliver poll cards across the whole city. However, it would appear that some were not received.

“The returning officer is urgently establishing the facts and will disclose to the agents, for all the political parties, those facts.

“The parties can then decide for themselves whether they wish to challenge the result.

“The declared result can only be challenged by a petition to the High Court.

“In the absence of a successful petition the result is, in law, good and valid.”

Adrian Arbib, who lives in Jericho, said: “A lot of people didn’t get polling cards – I didn’t get one myself.”

Referring to the poll in East Oxford, Thames Valley Police spokesman Chris Kearney said: “We can confirm that we are in consultation with the returning officer for Oxford City Council regarding the East Oxford count and are in an early stage of our investigation.”