OTTAWA, Dec 17 (Reuters) - Canadian Liberal Prime Minister Justin Trudeau is under increasing pressure to quit after Finance Minister Chrystia Freeland resigned over a policy clash on Monday, setting up one of the worst crises of his nine years in power.

Calls are growing from within the Liberal caucus for Prime Minister Justin Trudeau to step down as party leader — and some have pegged Chrystia Freeland as their choice to replace him.Twenty-one Liberal MPs have publicly urged Trudeau to resign — many of them within the last week — after Freeland shocked Canadians on Monday by resigning as deputy prime minister and finance minister hours before she was supposed to table the government's fall economic statement.