Leaders of the Southern African Development Community (SADC) meeting at an emergency summit in South Africa today will be hoping that their intervention will finally break the political deadlock between Zimbabwe's two main parties, ZANU-PF and the Movement for Democratic Change (MDC).

But they are unlikely to succeed if they continue to ignore the responsibility of ZANU-PF and President Robert Mugabe, for the impasse and the country's ongoing political and humanitarian crisis.

The two parties differ sharply over the allocation of new cabinet positions, largely because ZANU-PF wants to relegate the MDC to junior partnership in the new power-sharing government.

On October 11, ZANU-PF, without the consent of the MDC and contrary to the agreement, published a list of cabinet appointments. Mugabe allocated all senior ministries - including home affairs, foreign affairs and justice, as well as defence and finance - to ZANU-PF.

The MDC rejected the ZANU-PF list and released its own.

ZANU-PF's insistence on retaining control of the most powerful ministries at the expense of equitable power-sharing is a clear sign that the party is not yet committed to bringing an end to the country's crisis.

Despite the power-sharing agreement, the politically motivated violence by ZANU-PF and its allies persists. Human Rights Watch has found that the ZANU-PF-controlled police continue to use violence to break up peaceful protests, and routinely persecute opposition activists.

A brazen example was the break-up of a peaceful demonstration by women's rights activists last month, as SADC leaders, including the presidents of Mozambique and South Africa, were visiting the country to try to end the political deadlock.

Also last month, police in Bulawayo assaulted and arbitrarily arrested and detained several members of the organisation Women of Zimbabwe Arise.

Its leaders, Jenni Williams and Magodonga Mahlangu, spent three weeks in custody before they were finally released on bail.

Contrary to Mugabe's accusations that Zimbabwe's humanitarian situation is a result of international sanctions, the situation has been severely exacerbated by his party's abusive policies and actions.

The time has come for SADC leaders to take a tougher stance. They should start by strongly condemning ZANU-PF's role in the ongoing abuses and the lack of good faith that the party has shown in improving the country's humanitarian situation.

They should also acknowledge that the mediation efforts of former South African president Thabo Mbeki have run their course and immediately appoint a new mediator and set specific benchmarks and timelines for resolving the crisis.

They should also support a stronger role by the African Union and the United Nations, using their expertise, monitoring capabilities and ability to bring pressure where needed.

By finally showing clear leadership, SADC leaders can help bring an end to the suffering of Zimbabweans and restore normality to the country.

Tiseke Kasambala is a senior researcher in the Africa division of Human Rights Watch.