* Conservatives alarmed at Macron poaching
* Hamon says left-wingers don't belong in a Macron government
* Cabinet line-up expected Wednesday (Adds sources on possible ministers, Macron meetings)
PARIS, May 16 (Reuters) - A leading French conservative accused President Emmanuel Macron of "dynamiting" the political landscape on Tuesday as he put together a government that is expected to include former rivals on both left and right.
Macron wants to break through the left-right divide that has dominated the euro zone's second-largest economy for decades, and so is drawing in figures from outside his year-old centrist Republic on the Move (REM) party to complete his list of ministers, expected on Wednesday.
"We want to bring people together, beyond old divides that have become pointless," REM's secretary-general Richard Ferrand told France Inter radio.
The divide-and-conquer tactics by the centrist Macron, elected on May 7, are spreading alarm in the Socialist party and the conservative Republicans (LR), both of which are still licking their wounds after their presidential defeat.
They fear he will poach more of their leading figures as he tries to widen his political base before crucial parliamentary elections in June.
In a sign of that concern, LR senior lawmaker Francois Baroin disowned party colleague Edouard Philippe for accepting Macron's offer of the job of prime minister on Monday.
"What Emmanuel Macron is proposing is dynamiting not political reshaping," Baroin told BFM TV.
Baroin is leading LR's campaign for the parliamentary elections, which will be key for his party's future as well as Macron's chances of carrying out his pro-business, pro-EU policies.
Benoit Hamon, who gathered just over 6 percent of the votes for the Socialist Party in the first round of the presidential election in April, said left-wingers did not belong in the upcoming government.
"Who can think that the Left will pull itself together if it is part of a coalition led by a member of The Republicans party?" he said.
But the list of those tipped to be part of the government included veteran Socialists, as well as conservatives, centrists and newcomers to French politics. Macron has said he wants a team of maximum 15 ministers, fewer than in the outgoing Socialist administration.
Initially expected for late Tuesday, the announcement of who will be part of the government was postponed to 3 p.m. Wednesday (1300 GMT). The president's office said Macron wanted to allow time for thorough checks on the ministers' background, including their tax situation, and avoid conflicts of interest.
Among the names being touted by French media are three veteran socialists: outgoing defence minister Jean-Yves Le Drian and ex-World Trade Organisation boss Pascal Lamy. Le Drian with Philippe on Tuesday, giving weight to talk that he could keep his job.
There are also centrists, including Modem party leader Francois Bayrou and EU lawmaker Sylvie Goulard, a former adviser to former European Commission president Romano Prodi.
Conservatives whose names are being floated include LR lawmaker Nathalie Kosciusko-Morizet, as well as Thierry Breton, who was economy minister under conservative President Jacques Chirac.
Among possible civil society nominees is Nicolas Hulot, a popular former TV documentary star turned environment activist, who helped prepare the 2015 United Nations COP21 climate summit in Paris. A spokesman for Hulot told Reuters he was in talks with Macron but that nothing had been decided.
An overwhelming majority want politicians from the Left, Right and centre to be included in the government, a Harris Interactive poll showed on Tuesday.
But in a sign of how little known France's new prime minister is, 57 percent of those surveyed said they did not know him well enough to say if his appointment was a good or a bad thing, while just under a third said it was a good thing.
Some conservative lawmakers said they doubted Macron could poach any big names. "The heavyweights won't give in," a source close to former prime minister Alain Juppe said.
But over 20 LR members of parliament, including some party heavyweights and former ministers, issued a joint statement on Monday urging the party to positively respond to the "hand extended by the president".
While the head of France's main employers group Medef, Pierre Gattaz, said Macron's first days in office were "faultless", the head of the country's largest union, the CFDT, warned him not to "go at it with an axe" to carry out his planned business-friendly reforms.
"No one wants him to fail. We don't know what would happen if he did, there could even be violent clashes," he told Les Echos daily in an interview, urging him to consult unions.
Macron was to meet U.N. Secretary General Antonio Guterres on Tuesday evening to discuss issues including Syria and climate change, and he is set to visit French troops in Africa on Friday, sources said.
(Additional reporting by John Irish, Richard Balmforth, Marine Pennetier; Editing by Andrew Callus and Ralph Boulton)