OTTAWA -- The integrity of Canada's electoral process is at "serious risk" due to rampant procedural errors made by polling officials, a report commissioned by Elections Canada says.

The report blames overly complex rules and poorly trained polling officers for "serious errors" in 54 per cent of the paperwork filled out during the 2011 federal election for electors who needed to prove their eligibility to vote.

The report, by former British Columbia chief electoral officer Harry Neufeld, includes the results of a national audit of the documentation filled out for electors whose names were not on the list of registered voters or who failed to bring the required identification with them to their polling stations.

In those cases -- about 15 per cent of electors -- polling officials were required to administer special procedures, such as the swearing of oaths or having someone vouch for the voter's identity.

The audit found serious errors -- the kind that can lead courts to overturn election results -- in 12 per cent of voter registration paperwork and in 42 per cent of vouching paperwork.

"The audit indicates that the applications of specific legal safeguards, in place to ensure each elector is actually eligible to vote, were seriously deficient in more than 165,000 cases due to systemic errors made by election officials," the report says.

On average, that amounts to more than 500 serious administrative errors in each of Canada's 308 ridings.

"Obviously, this is unacceptable," Neufeld concludes. "Aside from legal concerns, public trust in proper administration of the electoral process is at serious risk if these errors are not addressed."

Still, to keep the problems in perspective, the report notes that more than 12 million Canadians cast ballots on May 2, 2011, and irregularities occurred in only 1.3 per cent of the cases.

Elections Canada commissioned the report six months ago amid controversy over myriad procedural irregularities in the Toronto riding of Etobicoke Lakeshore.

Borys Wrzesnewskyj, the Liberal incumbent who lost in 2011 to Conservative Ted Opitz by a mere 26 votes, challenged the results in court. The Ontario Superior Court found the irregularities sufficiently widespread that it declared the result null and void.

However, the Supreme Court of Canada subsequently reversed that decision.

Neufeld says there are multiple causes of all the errors, among them the reality that "200,000 election officers need to be recruited and trained, most often for a single day's work that happens only once every few years."

That said, the "widespread consensus" among those interviewed by Neufeld was that the rules governing special voting procedures are much too complicated.

Over the long term, he says the entire voting services model needs to be overhauled. But since that can't be done in time for the next federal election in 2015, he suggests some interim steps be taken to simplify the process and ensure greater compliance with the rules.

Among other things, Neufeld recommends a campaign to encourage electors to ensure they're on the voters' list prior to election day; putting a supervisor in charge at every voting site; simplifying written instructions for poll officers and better training for election officials.

In a written response to the report, chief electoral officer Marc Mayrand accepts Neufeld's findings and says Elections Canada is working on solutions.

"The compliance review (by Neufeld) has highlighted the vital role that accuracy in electoral administration plays in public confidence in our electoral system and the results it produces," Mayrand says.

"Elections Canada agrees with Mr. Neufeld's finding that significantly improving rates of accuracy among election officers administering procedures on election day requires a fundamental redesign of the current voting services model."