Some polling stations ran out of ballot papers yesterday because of the unexpectedly high turnout.
Electors in the Liverpool Wavertree constituency were told they had to wait for new forms to be delivered before they could cast their votes.
Returning officer Colin Hilton apologised for the problem but insisted everyone who wanted to vote “had the opportunity to do so”.
But local councillors reported that at least one polling station in the constituency was closed for an hour and said some people who were turned away did not return to vote later.
Mr Hilton, who is also chief executive of Liverpool City Council, said: “Due to unprecedented and unexpected high turnout in the Wavertree constituency, a small number of polling stations ran out of ballot papers in the early evening.
“As is normal procedure in these circumstances, additional ballot papers were delivered very swiftly to these stations. The very high turnout has caused similar problems in other parts of the country.”
In 2005 Liverpool Wavertree was held by Labour with a majority of 5,173 on a turnout of 50.8%.
But boundary changes in effect cut the majority and the Lib Dems made it a target this year.