About DMP

Dual Member Proportional (more formally known as Dual-member Mixed Proportional) is a proportional electoral system that was created by Sean Graham in 2013 with funding from the University of Alberta. It was designed to meet Canada’s unique needs and to build support for proportional representation.

With DMP, Canada’s current single-member districts would be replaced with about half as many dual-member districts. All candidates would run in their local dual-member district, and voters would choose their preferred candidate or pair of candidates using a straightforward single-vote ballot. The first seat in every district would go to the local candidate with the most votes, while the second seat would be filled to create a proportional election outcome. Elected candidates would be responsible for representing their dual-member district and would rely on their local constituents’ votes for re-election.

DMP has many advantages over other proportional electoral systems. Some of the most noteworthy improvements are:

  • Keeping the simple ballot design of Canada’s Single Member Plurality electoral system
  • Eliminating the need for long party lists
  • Retaining a higher degree of local representation and accountability
  • Not increasing in complexity from the voter’s perspective as region size increases
  • Reducing parties’ recruitment burden
  • Satisfying the Senate clause when multiple provinces are included in one region

For an overview of how DMP would work at the federal level in Canada, check out the five-minute video found below. For further information, see the FAQ and How It Works pages.

Thank you to the Ryerson University students who animated and produced this video.

The 2018 BC Electoral Reform Referendum

On May 30, 2018, the Attorney General of BC released the How We Vote report, which recommended that DMP appear in the 2018 referendum on electoral reform. This will be the second time DMP has been included in a public vote of this kind.

Of the Attorney General’s DMP specific recommendations, four are particularly important:

  1. The province-wide vote will be used to determine each party’s seat allotment.
  2. The geographically largest rural districts will remain as single-member districts. Votes cast in these districts will contribute to the province-wide total, ensuring that every vote counts.
  3. Independent candidates will be elected if they place first or second locally.
  4. A province-wide threshold will be set at 5%.

These key recommendations ensure that DMP would produce highly proportional results at the provincial level, address the concerns of rural British Columbians around district size, and be fair to independent candidates.

Sean Graham appeared on the July 12, 2018 edition of the PolitiCoast podcast to talk about DMP and the BC electoral reform referendum. This interview can be heard below.

PolitiCoast Episode 94: Sean Graham’s Dual Member Proportional

DMP and Federal Electoral Reform

On September 29, 2016, Sean Graham appeared as a witness before the Special Committee on Electoral Reform to present DMP. His submission to the Committee can be viewed on the Government page or by clicking here. To hear his testimony, listen to the audio clip below.

The PEI Plebiscite on Democratic Renewal

On November 7, 2016, the plebiscite on democratic renewal in PEI concluded. As a result of the recommendations made by the Special Committee on Democratic Renewal on April 15, 2016, DMP was one of the five options Islanders were able to choose from. The other four options were First-Past-The-Post (FPTP), First-Past-The-Post plus Leaders (FPTP+), Mixed Member Proportional (MMP), and Preferential Vote (PV).

According to the Interim Report of the Chief Electoral Officer, DMP received a significant level of support in this plebiscite. In the initial round of counting, DMP received nearly three times as many votes as FPTP+ and more than twice as many votes as PV. By the third round, DMP had taken 41% of the vote for change. The majority of the votes cast for DMP were then redistributed to MMP, pushing it over the edge to win the plebiscite. However, it is important to note that 26% of DMP’s supporters chose not to endorse MMP. This demonstrates that DMP was able to bring a significant number of people on board with reform that MMP could not.

Further evidence of DMP’s broad appeal can be found by looking at the distribution of the second choice preferences. DMP was the second choice of more voters than any other option. Moreover, DMP received more first and second choice votes than FPTP, suggesting that it has broader support than the current system.


Sean Graham holds two Bachelor of Science degrees from the University of Alberta and can be contacted by email at

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