At the heart of the C$400-million dollar lawsuit is Bill C-23, which imposed a retroactive cutoff date of January 1, 1998 for survivor pension benefits to those whose gay or lesbian partners had passed away. The bill was initially passed in 2000, according to an Associated Press report.

Having a retroactive benefits recovery date at all is generous enough, the Canadian government contents and is in step with the evolving legal status of same-sex relationships. However, lawyers representing the nationwide class told an Ontario Superior Court Judge in this case that “almost equal is not equal,” as the group is seeking benefits to be retroactive to April 17, 1985, the date equality guarantees were included in the Canadian Charter of Rights and Freedoms.

The trial begins after a Canadian judge gave approval last December for the nationwide class action suit to proceed on behalf of gays and lesbians, combining two separate suits launched in British Columbia and Ontario. A lesbian and four gay men were appointed as representative plaintiffs of same-sex partners who were denied survivor pensions. The trial is expected to last four weeks.