Defeated MP Megan Leslie calls the NDP losses on election night "devastating," and says Tom Mulcair must remain as leader to keep what's left of the caucus intact.

The two-term Halifax MP lost her bid for re-election to Liberal rookie, Andy Fillmore, by 7,617 votes.

Leslie is one of a number of high-profile NDP MPs whose defeat surprised Canadians. Jack Harris, Paul Dewar, Peter Stoffer and Peggy Nash also lost their seats.

"There was a Liberal wave that started in the Atlantic and it hit all of us," Leslie told CBC Power & Politics host Rosemary Barton.

"I do think it was a devastating loss. We were Official Opposition. We lost a lot of really great people."

Leslie chalks the red wave up to strategic voting, which she says the Liberals used to their advantage to target urban NDP-held ridings in Toronto, Halifax and Ottawa.

New Democrat Megan Leslie speaks with supporters after losing the riding of Halifax to Liberal Andy Fillmore. Leslie served as the deputy leader of the party under Tom Mulcair. (CBC)

"People with the best of intentions do believe that there is very little policy difference between the Liberals and the NDP. You know, six of one, half dozen of the other. I disagree with them but unfortunately that's how it's painted."

Faced with the loss of the next generation of potential leaders, Leslie says what the NDP caucus needs right now is stability. That means keeping Tom Mulcair as leader.

"It's time to just take a deep breath and I think Tom at the helm is a positive thing. He can keep us steady," Leslie said.

Mulcair will face a leadership review by party members in April 2016. Leslie says a decision on whether he stays on to fight the next election will be made by the leader and the party members.

Cross-bench friendships prove fruitful

Leslie was first elected to represent Halifax in 2008, when former NDP leader Alexa McDonough retired.

She championed issues like national pharmacare and suicide prevention. Her opposition day motion to classify plastic microbeads as toxic passed the House unanimously in March this year.

Among the many high-profile politicians defeated on election night, Leslie is one of the most well-known and well-liked across party lines.

Her ability to work with the former Parliamentary Secretary to the Minister of the Environment, Conservative MP Michelle Rempel, resulted in a bill that created Sable Island National Park Reserve.

Megan Leslie also teamed up with Conservative MP Lisa Raitt to sing comedy duets, notably at the Press Gallery Dinner in 2014, where they spoofed each others' party leaders and platforms.

MPs Megan Leslie and Lisa Raitt sing 'I Got You Babe,' at the Press Gallery Dinner in 2014. 1:53

Outgoing Transport Minister Lisa Raitt paid tribute to Megan Leslie on Power & Politics, wishing her well on her future endeavours.

"I am sure they are going to be great, but most of all, they are going to be good," Raitt said.

That comment left the outgoing MP for Halifax in tears.

To watch the entire interview with Megan Leslie, click on the player above.