By Adrian Croft
PARIS (Reuters) - A French junior minister backed Emmanuel Macron's presidential campaign on Tuesday, the first government member to do so, just hours after he reinforced his status as favourite in the first of a series of TV debates.
Biodiversity minister Barbara Pompili, from the ecology party, is expected to be the first of a number of ministers in Socialist President Francois Hollande's government to endorse the independent centrist instead of lining up behind Socialist candidate Benoit Hamon.
Bernard Poignant, a close adviser to Hollande, also told Reuters he was backing Macron.
Some Socialists see the 39-year-old Macron, a former economy minister under Hollande, as better placed to defeat far-right leader Marine Le Pen than left-winger Hamon, and more in tune with their views on how to revive the economy.
"I've decided after weighing it up seriously to back the endeavour, the programme and the candidacy of Emmanuel Macron," Pompili told France Info radio.
Around 50 Socialist lawmakers sponsored Macron for his election bid, according to French media reports.
Several opinion polls found Macron, a former investment banker who has never previously run for elected office, was the most convincing performer in a three-hour debate on Monday night watched by almost 10 million people - over a fifth of the French electorate.
Investors who had retreated to safe assets on worries that Le Pen would win and try to take France out of the euro sold the lowest-risk euro zone government bonds on Tuesday, relieved by Macron's debate showing. The euro rose against the dollar.
"There were some doubts whether Macron would perform well because of his relative inexperience, but the poll after the debate shows him in the lead," said DZ Bank analyst Rene Albrecht.
Twenty-nine percent of viewers thought Macron was the most convincing of the five candidates taking part, ahead of firebrand leftist Jean-Luc Melenchon with 20 percent, while Le Pen and conservative Francois Fillon were tied for third, a snap survey conducted online by Elabe pollsters towards the end of the debate showed. Hamon came in last.
An Opinionway poll said 24 percent of viewers found Macron the most convincing, ahead of his closest rivals Le Pen and Fillon, both on 19 percent.
Macron also scored well when viewers were asked how the debate had affected their views of the candidates. Twenty-nine percent had a better opinion of Macron, compared with 19 percent who had a worse opinion, Opinionway found.
Another snap poll, by Harris Interactive, also found Macron to be the most convincing debater.
An Opinionway survey taken partially after the debate found little change in voting intentions with Le Pen tipped to win 27 percent of the vote in the April 23 first round, three points ahead of Macron. The poll found Macron would easily beat Le Pen in the May 7 runoff.
The campaign has been highly unpredictable with Fillon, the one-time front-runner, sliding in the polls since allegations surfaced that he had paid his wife hundreds of thousands of euros of public money for little work.
While French legislators are allowed to hire relatives as assistants, the Fillon affair has put the practice under the spotlight.
France's financial prosecutor opened a preliminary inquiry on Tuesday into reports Interior Minister Bruno Le Roux hired his student-age daughters for summer jobs while a member of parliament.
Le Roux was also summoned to see Prime Minister Bernard Cazeneuve over the reports he hired his daughters.
Le Pen went on a two-day visit to Chad to meet French troops conducting anti-insurgency operations there. She will also hold talks with Chad President Idriss Deby and give a speech on French relations with Africa.
Although he was at times assertive during the debate, delivering blows to his rivals, Macron, who has less experience of such debates, also got bogged down in details at times, appearing vague and exposing himself to criticism.
He clashed on immigration and Europe with his main rival, National Front leader Le Pen.
(Reporting by Andrew Callus, Adrian Croft, Ingrid Melander, Gerard Bon, Chine Labbe, John Irish, Sudip Kar-Gupta, Brian Love; Editing by Richard Balmforth)