Why have so many Canadians turned on their PM?

Prime Minister Justin Trudeau of Canada is under intense pressure to step down after the abrupt and acrimonious resignation of a key deputy on Dec 16 highlighted his deep unpopularity after nearly a decade in power.

On Dec 20, as Mr Trudeau tried to save his leadership by rearranging his Cabinet, another prominent political ally turned on him, calling him a failed leader and vowing to bring down his government.

The ally, Mr Jagmeet Singh of the New Democratic Party, released a scathing letter promising to bring a motion to defeat the government in the House of Commons after Parliament returns from a holiday break in January.

According to a new poll by Ipsos, 73 per cent of Canadians think that Mr Trudeau should resign as leader of the Liberal Party, including 43 per cent of Liberal voters.

Here is what to know about Mr Trudeau's rise and fall, and what could happen next.

WHO IS JUSTIN TRUDEAU?

Mr Trudeau grew up in the spotlight as the son of Mr Pierre Elliott Trudeau, a former Canadian prime minister. In 2015, at the age of 43, the younger Trudeau became Canada's second-youngest leader after his Liberal Party won a strong parliamentary majority.

Mr Trudeau was savvy with social media and enjoyed a long political honeymoon after his election. (He also had good hair.)

In 2017, Mr Trudeau came under pressure to stand up to Donald Trump, the newly elected US president. As Trump restricted immigration, Mr Trudeau restated Canada's openness to asylum seekers, proclaiming that "diversity is our strength".

During his time in office, he prioritised two issues. One was climate change. The other was reconciliation with indigenous people, over the generational harms from a system of boarding schools that were rife with abuse. He also followed through on a pledge to legalise marijuana.