A battle is shaping up inside Tory ranks ahead of the party's national convention next month, once again pitting members of the old Canadian Alliance party against former Progressive Conservatives in Quebec and Atlantic Canada, the Canadian Press has learned.

The matter has even prompted Defence Minister Peter MacKay, one of the founding fathers of the Conservative party, to speak out in a letter to fellow Conservatives.

At issue is the "deal-breaker" policy that brought the two parties together in 2003 — the concept that all riding associations would be treated equally during a leadership and policy conventions no matter how many members they had.

The rule was important to Progressive Conservatives because it would keep a check on the power of large western Canadian associations that could easily swamp a leadership vote.

Delegate voting rule From the Conservative Party of Canada constitution: 7.5 The following shall be entitled to vote as delegates to a national convention: 7.5.1 an equal number not exceeding 10 from each electoral district association elected in such number and in such manner as determined by National Council which shall include a requirement that at least one such delegate reflect youth participation, and as an additional delegate the president of the electoral district association as of a date set by National Council;

One proposed amendment, from Immigration Minister Jason Kenney's electoral district association, would rewrite that subsection this way (changed or new wording in bold): 7.5.1 Each electoral district with 100 or more members in good standing will be allocated a maximum of ten delegates, elected in such manner as determined by National Council, which shall include a requirement that at least one such delegate reflect youth participation, and as an additional delegate the president of the electoral district association as of the date set by National Council. Electoral districts with fewer than 100 members in good standing will be allocated one delegate per ten members up to a maximum of nine delegates, also elected in such manner as determined by National Council. Kady O'Malley has more on the proposed party constitution changes, including full list of submissions, in her blog.

But now several riding associations, including Immigration Minister Jason Kenney's and Ontario MP Scott Reid's, want to alter the rules to move the party toward a system closer to that of "one member, one vote." Both Kenney and Reid were former Canadian Alliance members.

MacKay, who has fought aggressively at previous conventions against such amendments to the party's constitution, is calling on riding presidents to keep the proposals from even making it to the convention floor.

'Divisive debate' not needed: MacKay

"This is a divisive debate our Party does not need to have again, having rejected similar proposals in our founding agreement, and at two national conventions," MacKay wrote on May 17 in an email obtained by The Canadian Press and CBC News.

"Our membership has repeatedly spoken on this issue, and we should treat the matter as closed and move on to building upon our cross-Canada successes instead of weakening the foundation upon which those successes have been built."

Quebec Tories are also angry about the amendments, with some viewing it as the possible final nail in coffin of the party in the province after a disappointing election campaign there. Already, riding association presidents fear they won't be able to encourage dispirited members to be delegates at the June convention.

"Quebecers see it as them being forced out of the party," said Peter White, a longtime party member and riding association president in the Quebec riding of Brome-Mississquoi.

"I think it would be terrible, it would be a disaster."

White also calls the moves shortsighted, saying the numbers of members in a particular riding association goes up and down over different periods of time.

Bernard Cote, riding association president in a Montreal-area riding, said he was alarmed by the resolutions.

"We want to ensure that we'll be able to elect a leader who is representative of all the regions of the country, and that's why we insist on the rule of the equality of the ridings," Cote said.

But Ontario MP Gord Brown, a supporter of the equality of the ridings, doubts that the issue will occupy much space at the convention.

"I don't think this is going to be a big issue," Brown said. "What they're really going to do is celebrate the election victory."

Weighting of ridings proposed

Under the current system, each electoral district association is weighted the same when it comes to calculating support for a leadership contestant.

The proposal from Reid's association, according to party documents obtained by The Canadian Press, would weight the votes from an association based on how many members they have.

Kenney's riding is proposing that only associations that had 100 or more members in good standing would get to send the full slate of delegates to a convention.

"The reason for the amendment is that there is a sense of inequality in some ridings with respect to equal voting rights for all ridings when some ridings are larger than other ones, and other memberships in various ridings are in relative terms quite small," said John MacNeil, former president of the Calgary Southeast Conservative association.

"There's a sense of lack of proportionality."

Such a change to the constitution would take the support of a majority of delegates and a majority of delegates from each of the individual provinces.

Reid did not immediately return a message, nor did the Conservative Party of Canada.