Surveys suggest the French Socialists could make the same mistake as the British Labour Party and lurch to the left next year, taking themselves out of contention for the presidential and parliamentary elections that due in April and May.

Arnaud Montebourg, a fierce anticapitalist and former economy minister, is neck and neck with Prime Minister Manuel Valls, the center-left candidate, in the polls.

Ifop and Harris Interactive both give Valls 51 percent support in a hypothetical runoff against 49 percent for Montebourg.

Two Ipsos surveys conducted earlier this year put Montebourg ahead.

There is little doubt these two men will prevail in the first voting round.

Open contest

Valls, an economic reformer and hardliner on security policy, is more popular both inside the ruling Socialist Party and with the electorate at large.

The Harris Interactive survey shows that two-thirds of regular Socialist Party voters plan to back Valls in the primary.

The reason Montebourg could nevertheless best him is that the contest will be open to all self-declared leftists.

That, too, will sound familiar to British socialists. Their party twice elected the far-left Jeremy Corbyn as its leader, despite him having little to no support from fellow lawmakers or the Labour Party cadre. Corbyn triumphed because the party allowed voters to join specifically for the purpose of taking part in the leadership contest. Labour is now politically irrelevant.

First-round electoral math

Given the unpopularity of the Socialist Party government, neither Montebourg nor Valls would likely qualify for the second voting round of next year’s presidential election. Polls predict the runoff will pit the center-right’s François Fillon against the far right’s Marine Le Pen.

But a Montebourg candidacy could hurt Socialist Party candidates down the ballot and cede the center ground to Emmanuel Macron, his successor as economy minister who is running as an independent.

Macron polls better against Montebourg, who would even place behind the far-left Jean-Luc Mélenchon, who is also running independently.

Mélenchon’s support is at a steady 11-12 percent, regardless of whom the Socialists nominate. His voters are not going to switch to Montebourg in the first round.

By contrast, it looks like many center-left voters will switch to Macron if the Socialists nominate Montebourg.

All of which can only guarantee a Fillon-Le Pen runoff.