MARKHAM, Ont. - All four candidates in the race to lead the Ontario Progressive Conservatives are calling on Ottawa to delay tax harmonization until after the next provincial election in 2011.

Two-time leadership hopeful Frank Klees surprised his rivals during a party debate Thursday night when he produced a letter he'd drafted to federal Finance Minister Jim Flaherty asking him to put off the transfer of $4.3 billion that's intended to grease the harmonization wheels.

The money is a key part of the deal Flaherty struck with the Liberal government in March to ease the transition when Ontario merges its eight per cent provincial sales tax with the five per cent federal GST in July 2010.

Klees called on his competitors, including Christine Elliott, Flaherty's wife, to sign the letter on the spot.

Elliott, who added her signature along with Tim Hudak and Randy Hillier, later dismissed the letter as a "cute stunt" designed to generate publicity for Klees.

"I think it's a little bit meaningless, because we've always said this is the wrong tax at the wrong time," she sniffed. "But there you have it."

The opposition parties have complained that the single tax will increase the cost of many goods at a time when consumers can least afford it.

Klees, who took aim at all three of his rivals during the debate, bristled at the suggestion that he had taken a cheap shot.

"Can't imagine what she could possibly mean about that," he said after the event. "It's a very serious issue."

Premier Dalton McGuinty won't "for one minute" implement the plan if he can't get his hands on the billions promised by Ottawa, he argued.

"My point very simply is, let's defer implementing this tax," he said. "Let's make it an election issue. Let's allow the people of Ontario to vote on this."

It would be "impossible" to repeal the merged tax if the Liberals go ahead with the plan anyway -- a move that would cost millions more, Klees said.

Instead, he said he would offset the pain by lowering the provincial sales tax rate to leave the harmonized tax at eight per cent.

Quebec, Nova Scotia, New Brunswick and Newfoundland and Labrador have already harmonized their sales taxes with the GST, a move that became politically unpopular for some when consumers ended up paying more for goods that were previously exempt from the provincial tax.

With Ottawa's help, the province will try to ease consumer pain -- and reduce the political fallout -- by sending cheques of up to $1,000 for families and $300 for single residents.

The last cheque will go out in June 2011, just a few months before voters head to the polls for an October election -- a prospect that may worry the Opposition Conservatives.

Hillier is the only leadership contender who has publicly vowed to undo tax harmonization, but hasn't provided many details on how he would do it.

Both Elliott and Hudak have said that it's the wrong time to bring in tax harmonization, but won't say whether they'll repeal it.

During the debate, Klees also took aim at Hudak and Hillier for their vow to scrap Ontario's Human Rights Tribunal.

Hillier and Hudak want to get rid of the tribunal and have discrimination cases heard in courts, while Klees and Elliott are against the idea.

Klees introduced a private member's bill in the legislature Thursday that he said would stop the commission from interfering in matters of free expression by repealing a key section of the human rights code.

The commission has been overstepping its original mandate and needs to be reined in, but not abolished, he said.

Hudak and Hillier are taking things too far and risk alienating the ethnic communities in key Toronto-area ridings in the next election, Klees said.

"Not only is that an overreaction, I believe it sends the wrong message about how we, as the Progressive Conservative Party, view the issue of human rights," he said in an earlier interview with The Canadian Press.

"We should be seen as defenders of human rights, not understood or perceived to be the political party that would undermine the very statute that ensures political rights."

Elliott and Klees are warning that scrapping the tribunal could tank as badly with voters as former leader John Tory's doomed election promise to fund religious schools.

But Hudak and Hillier argue the commission -- established in 1961 by a Tory government -- and the Human Rights Tribunal are trampling on individual rights and wasting taxpayer dollars on nuisance claims.

Much of the criticism stems from the commission's condemnation of a Maclean's magazine article in April 2008 that it deemed to be Islamophobic, even though it could not legally proceed to a hearing on the complaint.

The article, which suggested that Muslims pose a threat to North America, "promotes prejudice towards Muslims" and has a "negative impact" on Muslim communities, the commission said.

That drew the ire of critics, who complained the commission was pushing for more powers that would allow it to muzzle journalists and interfere with free speech.

Hillier was the first to float the idea of scrapping both the commission and tribunal in the provincial leadership race. Hudak announced his support for the idea weeks later, leading some to speculate he was trying to win over Hillier supporters.

The No. 2 spot on the leadership ballot could be crucial for victory if no candidate wins a majority of the vote on the first round of counting.

Party members will vote June 21 and June 25 using ballots that will ask voters to rank the candidates in order of preference.

Ballot boxes will be sealed and sent to the convention, taking place June 26 to 28, to be counted. The new leader will be announced June 27.