A Canadian Conservative Party speech-writer has resigned after Prime Minister Stephen Harper was accused of plagiarism in a speech he made in 2003.
Owen Lippert admitted he had been "overzealous in copying segments" of a speech in support of the invasion of Iraq by then-Australian PM John Howard.
Mr Lippert said neither his superiors nor Mr Harper, who was opposition leader at the time, had been aware.
The accusation comes half-way through a general election campaign.
Mr Harper, who has led a minority government since January 2006, called the snap election for 14 October last month, hoping to obtain a parliamentary majority, for which he needs to win 28 more seats.
The speech by Mr Harper was originally made on 20 March 2003 as the House of Commons in Ottawa held an emergency debate at the beginning of the US-led war in Iraq.
In the debate, Mr Harper urged Canada and the Liberal government to join the so-called "coalition of the willing".
Five years later at a campaign stop on Tuesday, a Liberal MP for Toronto, Bob Rae, accused the prime minister of plagiarism.
He said Mr Harper's 2003 speech was almost word-for-word two days before in Canberra by his former Australian counterpart, John Howard.
To prove the allegation, portions of the speeches were played side by side.
"In the interests of world peace and regional security... The community of nations required Iraq to surrender," Mr Howard said in his speech.
"In the interests of peace and regional security... The community of nations required Iraq to surrender," Mr Harper said two days later.
Mr Rae said the discovery was made by accident almost two months ago by Liberal strategists who were looking for similarities between Mr Harper's government and that of US President George Bush.
The Liberals said they did not release the information until Tuesday because they had been waiting to receive a videotape of Mr Howard's speech from Australia.