Error over 18,000 Wokingham election poll cards
About 18,000 people in Berkshire have been sent two poll cards in error ahead of local council elections in May.
Wokingham Borough Council's postal voters received a second card in what it called an "administrative error" with its distributors.
The Conservative-run council said the contractor had agreed to pay for the cost of the duplication.
The Liberal Democrats said the error was "par for the course" with the current council.
Lib Dem councillor Malcolm Armstrong added: "It's another example of when they have taken their eye off the ball.
"You can sub-contract jobs out but it is still your responsibility.
'Bit of nonsense'
"This is par for the course with this current council."
George Davidson, spokesman for the Labour party in Wokingham, said: "It is yet another mix-up by this council.
"People will have got very confused with receiving two cards."
The council said the error would not mean electors could vote twice or their vote would be jeopardised.
In a statement, it said poll cards were used to "alert electors" to the local election on 5 May as well as the alternative vote (AV) referendum, which is also taking place on the same day.
Conservative councillor Keith Baker accused the other parties of point scoring.
He added: "It is a bit of a nonsense. The contractors recognised their mistake and will carry the extra cost.
"You don't need the cards to vote, they just remind you to go and vote.
"If there were people who did not get their cards then that is a cause for concern rather than getting a duplicate."
One third of Wokingham Borough Council's 54 councillors are up for re-election.
The borough has a total electorate of about 121,000 people.