By Emile Picy and Sophie Louet
PARIS (Reuters) - France's Francois Fillon accused his opponents in the government on Wednesday of fomenting a scandal in an attempt to scuttle his presidential campaign, as a new poll showed him no longer favorite to win power.
The second negative poll since the weekend for the erstwhile frontrunner coincided with an emergency meeting at which he urged fellow conservatives to stick by him during an official inquiry into allegations he misused over a million euros of public money.
The scandal, which surfaced a week ago when a newspaper said the 62-year-old ex-prime minister had paid his wife Penelope 500,000 euros for work she did not seem to have done, forced Fillon to cancel a trip to Iraq and Lebanon to deal with the crisis.
The poll by Elabe pointed to rising support for far-right National Front leader Marine Le Pen and made centrist Emmanuel Macron the candidate now most likely to win the presidency, with voters appearing to desert Fillon in large numbers.
"We are facing an institutional coup d'etat," Fillon told The Republicans party lawmakers at a meeting, according to one who was present. "This operation does not come from within our own camp, this affair is coming from those in power".
Responding for the ruling Socialists, government spokesman Stephane Le Foll said the accusation was "not acceptable".
Despite Fillon's appeal to members of his party, one of them broke ranks publicly to say it was time to consider an alternative candidate.
"We're like the orchestra on the Titanic as it sinks," said Georges Fenech, a conservative lawmaker. "The only line of defense is the facts, not who started off the scandal."
Refusing to abandon his candidacy, Fillon told a business convention that he would fight the allegations "until the end".
Republican party bigwigs later rallied behind Fillon at a meeting, unanimously supporting him and ruling out the possibility of coming up with a plan B, conservative Senate leader Gerard Larcher said.
As tensions in his camp hit fever pitch, Fillon grappled with further accusations that took the total amount involved in the scandal to more than one million euros, and beyond his wife to two of his children.
It was a report in the satirical weekly Le Canard Enchaine that lit the fuse a week ago, accusing Fillon of paying half a million euros to his wife Penelope for work as an assistant that she appeared not to have done.
On Wednesday, the paper reported further sums paid to her and two of his children.
Fillon has said the work was genuine and that he will step down should preliminary inquiries lead to a full judicial investigation.
The couple and some of their associates have since been interviewed by police who continued hearings on Wednesday with others linked to the affair.
Wednesday's Elabe poll showed Fillon's score fell by 5-6 points to 19-20 percent for the first round of the presidential election, set for April 23. Voting intentions for Macron were unchanged or up 1 point to 22-23 percent. Le Pen's first round score was up by 3 points to 26-27 percent.
That scenario would prevent Fillon getting to the May 7 final round.
Elabe predicted Macron would beat Le Pen in the runoff with 65 percent of the vote. Should Fillon make the runoff, he too would beat Le Pen, but by a lower margin, at 59 percent.
However, another poll by Ifop Fiducial offered Fillon some relief by showing him with a slight edge ahead of Macron in the first round, which would allow him to reach the runoff where he would beat Le Pen.
The revelations are particularly damaging because of the squeaky-clean image that won Fillon his party ticket in last November's primaries, Yves-Marie Cann, head of political studies at Elabe, told Reuters. "These accusations are hitting at the load-bearing wall of his popularity."
The scandal has heightened investor concerns amid fears that Le Pen could win and take France out of the euro and the European Union.
On Wednesday, the jitters affected financial market measures of French state borrowing costs. The gap between French and Belgian government borrowing costs hit its widest since at least April 2008.
(Additional reporting by Michel Rose and Leigh Thomas; Writing by Andrew Callus; Editing by Brian Love and Janet Lawrence)