LAHORE, Pakistan (Reuters) - Pakistani opposition leader Benazir Bhutto called on Tuesday for military leader Pervez Musharraf to step down as president and said she would never serve as prime minister under him.

Bhutto has long called for Musharraf to step down as army chief and become a civilian president but it was the first time she had called for him to quit as president altogether.

"It is time for him to go. He must quit as president," Bhutto said in a telephone interview.

She was speaking from the city of Lahore where she was placed under house arrest hours before a planned protest against the November 3 imposition of emergency rule.

Military ruler Musharraf set off a storm of criticism when he imposed emergency. He suspended the constitution, sacked most judges, locked up lawyers, rounded up thousands of opposition and rights activists and curbed the media.

The crisis in nuclear-armed Pakistan has raised fears about its stability and its ability to focus on battling a growing Islamist militancy.

It was also the first time Bhutto, who has for months held power-sharing talks with Musharraf, ruled out being prime minister under him.

"I will not serve as prime minister as long as Musharraf is president," she said. "Even if I wanted to work with him, I would not have the public support."

"Negotiations between us have broken down over the massive use of police force against women and children. There's no question now of getting this back on track because anyone who is associated with General Musharraf gets contaminated," she said.

"Police are not just arresting people, they are breaking windows, breaking homes, humiliating the women, the mothers, the sisters, the wives," she said.

"The men whose wives have been mistreated, the women who have seen their spouses thrashed and beaten up in front of their eyes don't want us to have anything to do with General Musharraf."

Two-time prime minister Bhutto planned to lead a motorcade on a 270 km (170 miles) route from Lahore to Islamabad to demand that Musharraf quit as army chief, end emergency rule, reinstate the constitution and free detained activists -- including many from her party.

But about 4,000 police moved in overnight around the house, laying out coils of barbed wire, setting up barricades and blocking streets with trucks laden with sand.

A detention order was pasted on the gate.

"Her residence is an official jail now," said a senior officer outside the Lahore home where she was staying.

(Reporting by Simon Gardner; Editing by Robert Birsel and Sanjeev Miglani)