Just 17 days before the first round of elections, the survey by the Gallup organization found that in a direct run-off, Barak would win 50 pc of the vote to 42 pc for Netanyahu, his widest lead yet.

But eight percent of the 900 people queried were still wavering. The poll confirmed a steady rise in Barak's popularity in recent weeks and was the first time the Labor leader was credited with garnering half the vote.