The federal government has tapped a Quebec judge to head a public inquiry into allegations of foreign interference in Canada's affairs.

Two government sources, who spoke on the condition of anonymity to discuss matters not yet made public, confirmed that Quebec Court of Appeal Justice Marie-Josee Hogue will lead the probe.

Prime Minister Justin Trudeau says Public Safety Minister Dominic LeBlanc, who is also the minister for democratic institutions, is set to announce the public inquiry today.

Opposition parties have been demanding a public inquiry for months over allegations the Liberals failed to properly monitor and respond to attempts by foreign states, especially China, to meddle in Canada's affairs.

The Liberals initially named former governor general David Johnston as a special rapporteur to examine the issue and promised to follow his recommendations, including if he called for a public inquiry.

Johnston recommended against an inquiry, saying the fact that so many details could not be made public due to national security implications would not give Canadians the answers they want.