Anger as 500,000 ballot papers in the capital ruled invalid

More than half a million voting forms for the London mayor and assembly elections were filled out wrongly, prompting warnings that the capital's voting system needs to be overhauled.

More than half a million voting forms for the London mayor and assembly elections were filled out wrongly, prompting warnings that the capital's voting system needs to be overhauled.

Labour's Ken Livingstone comfortably fought off a challenge from Steve Norris, the Tory candidate, to secure his second spell in city hall. Labour lost two of its seats on the assembly, while the UK Independence Party (UKIP) gained its first foothold in London.

The announcement of the results on Friday night was held up as returning officers scrutinised the hundreds of thousands of forms that had been incorrectly filled in.

Voters were asked to record their first and second choice for the mayor by putting a cross in one column for each. A total of 56,862 (3 per cent) of first-choice selections were ruled invalid, while 329,090 (17.1 per cent) of second choices were ruled out. Common mistakes included putting both selections in the same column, leaving the second column blank or putting a cross through two boxes.

Electors also had two votes in the assembly elections, one for a constituency representative and one from a party list. A total of 118,535 (6.2%) of the former and 48,536 (2.5%) of the latter were rejected as invalid.

The Electoral Commission will study the London ballot as part of its examination of the "Super Thursday" elections, which included an experiment with all-postal voting in four English regions.

John Bennett, the deputy returning officer for Greater London, said it had became clear after the previous mayoral and assembly elections in 2000 that the city's voting forms needed to be improved.

"We just knew that what happened in 2000 wasn't right," he told the BBC yesterday. "We wanted to agree something between all parties that would be okay for 2004 because the Government only had a particular window of opportunity to change the legislation. We missed that window, we could not continue the dialogue; that dialogue must resume."

Among his suggestions is printing clearer guidance on the mayoral voting slips and issuing the constituency and city-wide forms for the London Assembly separately.

Bob Neill, a Tory Assembly member, said: "Let's look at the design [of the forms] again."

Once second-preference votes were taken into account, Mr Livingstone beat Mr Norris by 685,541 to 542,423 votes. Simon Hughes, the Liberal Democrat candidate, trailed in a distant third, with UKIP's Frank Maloney fourth. Darren Johnson, of the Green Party, was beaten into seventh place by the far-left Respect coalition and the hard-Right British National Party (BNP).

The re-elected mayor will have to deal with an assembly that is likely to be hostile to his programme, including his spending plans and proposals to extend the congestion-charging zone westwards into Kensington and Chelsea. The assembly now comprises nine Tories (unchanged), seven Labour members (down two), five Liberal Democrats (up one), two UKIP members (up two) and two Greens (down one).

Labour will have been alarmed to have won only 25 per cent of the vote in the capital, which is certain to be a key battleground in the general election expected next year. A slump in support on that scale could jeopardise as many as 20 Labour MPs with small majorities, although the great unknown is whether the "protest votes" cast for UKIP, Respect, the BNP and the Greens will return to the mainstream parties.