MEXICO CITY (Reuters) -- Mexico City's leftist Mayor Cuauhtemoc Cardenas
                  formally declared his candidacy for president, challenging the political right to accept 
                  his conditions for a broad opposition alliance.

                  "We want to know whether we who are going to form this coalition are in agreement.
                  ... All we need is a yes or a no (on the Party of the Democratic Revolution's agenda),"
                  Cardenas told some 15,000 cheering PRD members filling the National Auditorium
                  Sunday.

                  Opinion polls have shown Mexico's two main opposition parties, the PRD
                  and the center-right National Action Party (PAN), have slim hopes of ending
                  the seven-decade rule of the Institutional Revolutionary Party (PRI) in
                  presidential elections next July unless they forge an alliance.

                  But Cardenas, who failed in bids for the presidency in 1988 and 1994, and
                  PAN candidate Vicente Fox both seem less and less inclined to step aside
                  to let the other lead a coalition.

                  Cardenas, the first democratically elected mayor of Mexico's gigantic capital
                  city, dedicated much of his half-hour speech on Sunday to the notion of a
                  coalition but said such an alliance was "not the most important thing" for his
                  party.

                  He said that to form an alliance with the PRD, the PAN would have to
                  abandon its agenda of selling off the government-owned petroleum and
                  electric power industries.

                  The PAN would also have to agree to reverse its support of a bailout of
                  failed banks, agreed to after the 1994-95 peso crisis, that is costing Mexican
                  taxpayers tens of billions of dollars, Cardenas said.

                  "We propose a plural government," Cardenas said. He said that meant a
                  broad, coalition government, with Cabinet members from all the parties in
                  the alliance.

                  Fox has said that if he runs as coalition candidate and wins, he would not
                  necessarily include other parties in his Cabinet.

                  Cardenas also challenged the PAN to agree to put items for the coalition
                  platform to a popular vote and to hold a full-blown election to choose a
                  coalition candidate. Others have suggested polling a sampling of voters
                  nationwide rather than holding a more expensive election.

                  The coalition candidate -- or separate opposition candidates if the drive for
                  an alliance fails -- will run next year against a candidate from the PRI, to be
                  chosen in that party's first-ever open primary election on Nov. 7.

                  Cardenas is expected to take indefinite leave from his job as mayor after
                  giving his annual state-of-the-city address on Sept. 17 so he can dedicate
                  himself full-time to campaigning.

                  Although PRD rules allow a few more days for other candidates to register
                  presidential aspirations, Cardenas is seen as taking his party's nomination no
                  matter what.

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