The NDP has swept up seats formerly considered Liberal strongholds in byelections held in the Port Moody-Coquitlam and Chilliwack-Hope ridings on Thursday.

New Democrat Joe Trasolini met expectations and became elected MLA in Port Moody-Coquitlam after winning 54 per cent of votes, according to Elections BC. Liberal Dennis Marsden finished second with 30 per cent of votes and Conservative Christine Clarke came in last with 15 per cent of votes.

The traditionally anti-NDP riding of Chilliwack-Hope took a different turn as New Democrat Gwen O'Mahony won 41 per cent of votes. Liberal Laurie Throness trailed with 31 per cent of votes, Conservative John Martin with 25 per cent of votes and Libertarian Lewis Clarke Dahlby with 2 per cent of votes.

Premier Christy Clark responded to the loss of Liberal bastions in a written statement.

"It's never been clearer that only a unified free enterprise coalition can defeat the NDP. That's why we are focused on strengthening our coalition so that in the next general election voters will have a clear choice between the free enterprise coalition and the NDP," she said.

Support for the BC Liberals has fallen since Clark began her reign.

A recent survey by Angus Reid Public Opinion showed that only about half of people who voted for the BC Liberals in the 2009 provincial election would do as again with Clark as premier.

Pollster Mario Canseco told The Canadian Press earlier this month that dwindling support for the party could allow the NDP to "win seats that they never would have dreamed of winning."

With files from The Canadian Press