Cotonou (AFP) - A group of politicians and union leaders in Benin say they are opposed to Prime Minister Lionel Zinsou standing for the presidency, claiming he was "parachuted in" by former colonial power France.

Zinsou, a Franco-Beninese financier, quit last year as head of one of Europe's biggest investment funds to become prime minister of the tiny west African nation in a move that surprised many.

In November, he was named candidate for outgoing President Thomas Boni Yayi's Cowry Forces for an Emerging Benin (FCBE) party at elections on February 28.

A coalition of political and union figures, led by former head of state Nicephore Soglo, on Tuesday claimed there was a plot to "impose" Zinsou as a candidate and demanded France explain itself.

Zinsou, 61, spent most of his career in France where he notably served as current Foreign Minister Laurent Fabius' speechwriter when he was prime minister.

He is the nephew of former Benin president Emile Derlin Zinsou but his detractors still say he has little understanding of Benin and has not spent much time in the country.

Government spokesman Alassani Tigri described the claims as "unacceptable" and said they appealed to "hatred, racism, fear and intolerance".

"Our compatriot linked to these comments is a Benin citizen through and through. He is Franco-Beninese like a good number of our countrymen and women...

"No law of the land excludes his run for the presidency," he said in a statement.

Candidates have until January 12 to formally declare their intention to run.

Two prominent businessmen -- farm produce tycoon Sebastien Ajavon and Patrice Talon, who made his fortune in cotton, have already announced they will stand.

Talon was implicated in an alleged plot to poison Boni Yayi and returned from exile in France last year after receiving a formal pardon.