A senior aide to Prime Minister Justin Trudeau will carry the Liberal banner in a federal byelection next month.

The Liberal party says Mary Ng beat out two challengers Saturday in a nomination battle in the Toronto-area riding of

Markham-Thornhill.

Ng worked in the Prime Minister's Office as his director of appointments.

Ng, who came to Canada from Hong Kong with her family, does not live in the riding but grew up in nearby north Toronto.

The nomination battle was mired in controversy in the past week when another contender pulled out of the race saying it was set up to favour Ng.

Juanita Nathan was unhappy that the party set an early cutoff date to register new members, saying more than 2,000 people she signed up were ineligible to vote in Saturday's nomination.

The party said the nomination process was run in accordance with national nomination rules and Ng's camp said some members it signed up were ineligible as well.

The seat became vacant when Immigration Minister John McCallum quit to become ambassador to China.

The byelection will be held April 3.