Conservative Party leader David Cameron said today a new British government must ensure there was no repeat of chaotic election day scenes in which people were still queuing in their hundreds outside polling stations when the ballot boxes closed.
The Electoral Commission pledged a “thorough review” into problems around the country, including London, Sheffield, Manchester, Liverpool and Newcastle.
Prime Minister Gordon Brown was among a raft of politicians who expressed concern at the reports from some areas of queues up to two hours long and people being turned away from voting at 10pm in the face of high turnouts and low staff numbers at polling stations.
A spokesman for Gordon Brown said the Prime Minister was “very concerned by the reports and would support a thorough investigation into them”.
Making his victory speech in Witney, Oxfordshire, Mr Cameron thanked local officials in his constituency for a well-run General Election day, but said that had not been the case in some parts of the country.
“An early task for a new government is to get to the bottom of what has happened and make sure that it never happens again,” he said.
The Electoral Commission said it was a cause for “serious concern” that many people who wanted to vote were prevented from doing so, and that there should have been sufficient resources allocated to make sure everyone was able to vote.
There were angry scenes at polling stations in Hackney, east London, where would-be voters staged a sit-in after they were told they could not vote, and in Lib Dem leader Nick Clegg’s constituency of Sheffield Hallam, where students tried to prevent ballot boxes being taken to the count after they were turned away.
In some places, including two polling stations in Newcastle, voters were ushered into the building before 10pm when the doors had to be shut, while at one site in Lewisham, ballot papers were handed out to the queue before the deadline.
But there were reports in the Manchester Withington constituency of people queuing for more than two hours before being turned away because the polls had closed.
Jenny Watson, chairwoman of the commission, said the current system was “at breaking point” and the law might need to be changed as a result of the scenes witnessed last night.
Additional resources should have been deployed when it became clear that turnout was higher than anticipated.
And she said that if there were constituencies which had not followed the rules, they could be subject to challenges.
She said returning officers would have to “answer to us and answer to local voters”.
Ms Watson told BBC News: “The law is extremely clear. They have the guidance. They should have done what the law says.
“If they haven’t done that ... they may well be subject to election petitions.”
Labour’s deputy leader Harriet Harman said it would be “quite right” if some results were challenged because voters were turned away without being able to cast their ballot.
Branding the situation as “outrageous”, Ms Harman said: “If there is any close outcome that is going to be produced by that, there should be a legal challenge – and quite right too.
“It is fundamental that people get their right to vote.”
Arriving for the count of her Camberwell & Peckham constituency in south east London, she told the Press Association: “Everyone is entitled to get their vote.
“It is outrageous that people who were there long before 10pm at some polling stations have not been allowed to vote.
“They should have been issued with their ballot papers and been allowed to cast their ballot after 10pm.”
Tory party chairman Eric Pickles commented: “It’s ridiculous. Of course people should be able to vote.
“Surely to goodness the returning officers could have just put the people in the polling station and continued.”
Already, the two Labour parliamentary candidates in Hackney, where residents were voting for their MP, local councillors and borough mayor, have launched an official complaint over their supporters’ inability to vote.
A Hackney Labour spokesman said: “Hackney’s two Labour candidates to become MP, Diane Abbott and Meg Hillier, launched an official complaint to the borough’s returning officer tonight after Labour candidates relayed protests from life-long Labour supporters that their votes had been ignored.”
And in Sheffield, the returning officer John Mothersole apologised to voters for getting it “wrong”.
He said: “We were faced with a difficult situation with the numbers of people, and a large amount of students turning up to vote without polling cards.
“This made the administration process of ensuring the correct person was given a ballot paper much longer.
“The only remedy, which we could not take, was to extend the voting times,” he said.
Students in the constituency complained they had been treated differently from local residents by being put in separate, “slower” queues as polling station staff attempted to process crowds of voters.
Simon Hughes, the Liberal Democrat looking to be returned to his Bermondsey and Old Southwark seat in south-east London, called for ``a significant rethink'' of where polling stations are based to try to avoid the problems which blighted some of the counts.
It was “to be expected” there would be queues after people had finished work and just before the polls closed. Polling stations should be set up in supermarkets and even bus stops, he suggested.
He said: “I have always had a view that we need a much more modern system. In each constituency people ought to be able to vote at any polling station.
“We have one register that can be kept in polling stations. We also ought to have polling stations in places where people go like bus stops and supermarkets. It would mean that many more people would be able to vote earlier in the day and not have to go out of their way.
“I hope that what has happened prompts a significant rethink of where we put polling stations. We need to go on and encourage things to make it (voting) easier and quicker.
“Obviously today things were also slowed because there were two elections - the General and the local elections.”
Mr Hughes said he had no reports of any problems in his constituency.
Liberal Democrat leader Nick Clegg said he had visited some of the busiest polling stations in his constituency yesterday afternoon and seen hundreds of voters, particularly younger people, queuing for an hour and a half to vote.
“It is not right that hundreds later found themselves unable to exercise their vote when the polls closed. That should never, ever happen again in our democracy,” he said.