Former NDP premier Mike Harcourt came out of "semi-retirement" Friday to warn voters not to desert the party for the Greens.

Harcourt visited Oak Bay to back NDP leader Adrian Dix and local candidate Jessica Van der Veen, who is in a tight three-way contest with Green Party candidate Andrew Weaver and B.C. Liberal incumbent Ida Chong for the Oak Bay-Gordon Head seat in suburban Victoria.

Weaver, the University of Victoria climate scientist who has been the focus of the B.C. Green campaign for the May 14 election, chatted up voters on the opposite side of Oak Bay Avenue as Harcourt spoke to reporters Friday.

"I think if you vote Green, think again," Harcourt said. "You're going to be electing Christy Clark and four more years."

The NDP is the only party that can form a government and "defend our coast" against oil tankers, Harcourt said.

Harcourt shrugged off his last endorsement, which was for NDP leadership candidate Mike Farnworth in 2011. "You go left, you get left out," Harcourt warned party members then, suggesting that Adrian Dix was not the moderate candidate the party needed.

Harcourt said Friday he considers Dix, Farnworth and leadership candidate John Horgan to be friends, and any one would have been a good choice.

"I've watched Adrian Dix grow into a strong, capable leader of the NDP, and I believe he'll be a very good premier for British Columbia," Harcourt said.