An extremely wealthy Montreal man, accused of shutting his ex-lover out of $50 million in alimony, told a Quebec court Thursday that a proposal to marry the woman was nothing but an April Fool's joke.

The former couple, who can't be named because of a family court publication ban, lived together for ten years and had three children.

But since Quebec doesn't recognize the rights of common-law partners after separation, the woman has been left with next to nothing, according to her lawyer.

She's now seeking monthly child support payments of $56,000 plus a one-time payout of $50 million.

The case has taken on the character of a constitutional challenge and will likely have a profound impact on Quebec's unusual civil laws.

Lawyers expect that the case could go all the way to the Supreme Court of Canada and drastically alter the legal rights of millions of people across the province who are involved in "conjoints de fait" (de facto unions).

During their decade-long relationship, the wealthy and well-known businessman continually promised to get married, the 35-year-old single mother testified at Quebec's Superior Court.

Eventually, the man popped the question and the couple set their wedding date for April 1, 2001, court heard.

But according to the man's testimony, that date was simply a prank and he had never intended to marry her.

In fact, the man had always maintained that he was against the institution of marriage and never intended to tie the knot with the mother of his three children, according to testimony.

In a statement read outside of the court, the man also accused his former partner of mudslinging and trying to tarnish his reputation.

"I will not respond in kind to her testimony. She is the mother of our three children, and out of respect for her and our children, I refuse to engage in a public display of our private life and run the risk of damaging her reputation," the man's lawyer said, reading from a prepared statement.

However, once the man took the stand, he told the court that he has provided his ex with monthly child support payments of $35,000 since 2002.

He also said that he bought the woman a $2.5 million home in Montreal's Outremont borough, along with a luxurious condo abroad.

During earlier testimony, court heard that the pair started their relationship after meeting on a beach, abroad and that the woman gave up her career at home to start a family in Montreal.

So far, the battle has already cost the couple about $2 million in combined legal fees.

But the woman's lawyer, Anne-France Goldwater, said Thursday that battling Quebec's antiquated civil laws are the most pressing concern.

"If madam weren't in a situation where she could finance the case - because it's a case involving big money - the million or so women across Quebec who have no rights would continue silent, without a voice," said Anne-France Goldwater.

She added that many women in Quebec who have no legal rights have been left "without a forum, without a judge - and it's time it gets corrected and it will be corrected here."

With files from CTV Montreal's Stephane Giroux