The House of Commons voted down a private member's bill calling to amend the Criminal Code to charge someone for harm caused to a "pre-born child" when they are accused of harming a pregnant woman.

Bill C-225, known as Cassie and Molly's Law, is named after Cassandra Kaake. She was seven months pregnant when she was found dead at the scene of an arson in Windsor, Ont. in 2014. She had planned to name her child Molly.

The bill called for an amendment that would "make it a separate offence to cause injury or death to a pre-born child during the commission of an offence against the child's mother."

"There really aren't words for them, or for me, to express the huge disappointment in the government," said Cathay Wagantall, the Conservative MP sponsoring the bill.

Members of Kaake's family were staying with Wagantall in Ottawa during the vote, visiting Parliament for the last hour of debate and to watch the vote unfold.

"I've spent a lot of time with [Kaake's family] and that just fuels the realization of how important this bill was," Wagantall said.

Matthew Brush has been charged with first degree murder in Kaake's death. His case is now before the courts.

The bill failed to garner enough support to pass the House of Commons, with 209 MPs voting against the legislation, compared to 76 votes supporting it.