OTTAWA -- Prime Minister Justin Trudeau is on the speakers list next month at a celebrity-laden global concert promoting vaccine equality, but his appearance isn't sitting well with his political critics at home.

The Global Citizen Vax Live Concert to Reunite the World is being recorded May 2 in Los Angeles but will air on YouTube May 8. It is being hosted by Selena Gomez and will feature performances by Jennifer Lopez, Eddie Vedder and the Foo Fighters.

The Duke and Duchess of Sussex, who are raising money for the COVAX vaccine sharing facility, are also co-chairing the concert. U.S. President Joe Biden, Vice-President Kamala Harris and French President Emmanuel Macron are also scheduled to speak.

Trudeau's office confirms he will deliver a message virtually about the need for international co-operation to end the pandemic.

The concert's organizers are asking political leaders to commit to ensuring vaccines are available to every country.

Canada is one of the largest contributors to the global vaccine sharing initiative known as COVAX and has committed to donating excess doses from its own purchases once Canadians are vaccinated. But Canada has been criticized for also taking doses from COVAX despite having privately purchased enough vaccines to give as many eight doses to every Canadian.

Canadian opposition parties said Trudeau's participation in the concert is hypocritical.

"He's raiding a system that was put in place to help developing nations get vaccines (COVAX) because he failed to get Canadians adequate supply," Conservative health critic Michelle Rempel Garner said on Twitter. "And he has the gall to do this?"

NDP Leader Jagmeet Singh said "frankly it's outrageous" that Trudeau is appearing without supporting the calls from many poorer nations to lift patent protections on COVID-19 vaccines so they can be produced at more places and therefore available to more countries.

"Like what we need to do is fight to make sure that low-income countries can produce a vaccine, that we support them in a meaningful way," said Singh. "And doing this show is just ... exactly that, just to show, not really helping the people in need."

Green Leader Annamie Paul said she hopes Trudeau is speaking at the concert to change his mind about taking doses from COVAX.

"This is the time to show leadership," she said. "We have failed to do so, so far, but every day is a new day."

Trudeau has defended Canada's acceptance of COVAX doses, saying the facility was designed to encourage wealthier nations to donate to get doses for themselves and to help buy for other countries.

This report by The Canadian Press was first published April 28, 2021.