Manuel Zelaya was sent into exile following June's army-backed coup
Honduras's supreme court has rejected a Costa Rica-brokered deal to restore ousted President Manuel Zelaya to power and ordered his arrest if he returns.
The ruling also affirmed the legitimacy of the government of interim leader Roberto Micheletti.
The move comes on the eve of a planned visit by a delegation from the Organisation of American States (OAS), which backs the Costa Rican proposal.
It is unclear if the court ruling will affect the delegation's plans.
The court reminded Mr Zelaya that he faces several charges - including crimes against the government, treason, and abuse of power - and would be subject to trial if he re-entered the country.
It said Mr Micheletti's government had been installed as part of a lawful "constitutional succession".
Correspondents say Mr Micheletti is increasingly confident that he will be able to remain in power until elections at the end of November.
The ruling is a blow to a proposal mediated by Costa Rican president, Oscar Arias, to try to end the crisis.
Under the proposal, Mr Zelaya would be reinstated as president, while Mr Micheletti would return to his pre-coup post as the speaker of Honduras's parliament, and early elections would be called.
Mr Zelaya has been in exile since 28 June when he was forced from office amid a power struggle over his proposals for a public consultation on constitutional change.
His critics said the move was aimed at removing the current one-term limit on serving as president and paving the way for his re-election.