HARARE, Zimbabwe — Zimbabwe's High Court rejected an opposition demand Monday for the immediate release of results from last month's presidential election, an opposition lawyer said.

Opposition spokesman Nelson Chamisa said the party would go ahead with plans for a nationwide strike Tuesday.

The main opposition leader, Morgan Tsvangirai, says he won the March 29 election outright, and has accused President Robert Mugabe of holding back the results so he could orchestrate a runoff and ensure he maintains his 28-year grip on power.

Tsvangirai's Movement for Democratic Change had hoped that the court — stacked with Mugabe loyalists — would force the election commission to release the results.

"It's a very sad day in Zimbabwe," MDC lawyer Andrew Makoni said. "(The court) has given the Zimbabwe Electoral Commission a blank check. We don't know when the ZEC will be ready with results. We don't know what specific time would be reasonable in the eyes of the court."

Government spokesman Bright Matonga said he could not comment until he read the ruling.