Poll chaos: Courts may rule on battleground seats after voters turned away

The massive turnout inspired by the closest General Election for a generation caused huge problems as staff failed to cope with the numbers.

In Sheffield voters claimed they had queued for nearly three hours and still failed to get in as about 200 were turned away and similar problems were reported in London, Manchester, Newcastle, Birmingham and Bristol.

Yesterday the chairwoman of the Electoral Commission described the voting system as "Victorian" and said an investigation has been launched. Jenny Watson also said that if there were constituencies which had not followed the rules, they could be subject to challenges.

And human rights lawyer Geoffrey Robertson QC said that people denied the right to vote could take legal action.

Ms Watson said: "Clearly we are going to look at this. The Government is going to look at this. It may be that the law needs to change.

"We've been calling for better co-ordination, for power of direction for us to tell people what to do, for some time. We haven't been successful in persuading Government and Parliament to take that up so far.

"I hope that last night's experiences will persuade them there is a real need to look at our Victorian system and modernise it fit for a 21st century democracy."

As frustrations boiled over the police were called in and it later emerged that in some areas of the country polling stations were staying open past the 10pm deadline, whereas others had slammed the doors shut.

Sheffield returning officer John Mothersole apologised for getting it "wrong" and later there were also claims of discrimination in the city, with students reporting that they were separated from the main queue of "permanent residents" who were given priority.

The party leaders were united in their condemnation of the situation and said it should never happen again.

The law states that poll doors must close at 10pm and no ballot papers are issued after that time, although everyone who has a ballot paper by then must be able to vote.

After results in 603 of the UK's 650 constituencies had been announced, national turnout stood at 65 per cent, up from 61.4 per cent in 2005 and 59.4 per cent in 2001.

A spokesman for Gordon Brown said the Prime Minister was "very concerned by the reports and would support a thorough investigation into them".

Mr Cameron said a new government must "get to the bottom of what has happened and make sure that it never happens again".

Liberal Democrat leader Nick Clegg – who had angry voters at his constituency home following the problems in Sheffield – said the situation was simply not acceptable in a democracy.

The high turnout meant that in some areas election staff ran out of ballot papers with voters in Hull and Liverpool forced to wait for new forms to be delivered before they could cast their votes.

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 Sheffield Hallam, 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, south London, ballot papers were handed out to the queue before the deadline.

Ms Watson 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".

She said: "The law is extremely clear. They have the guidance. They should have done what the law says."