Support for Gaza's Islamist ruling party Hamas has dropped sharply in the aftermath of Israel's Operation Pillar of Defence, according to a poll by a Palestinian thinktank.

The overwhelming majority of Palestinians living in the occupied West Bank and Gaza - 90 percent out of 1,179 people interviewed in March - think that Hamas and its more moderate counterpart, Fatah, should reconcile themselves to each other, the Jerusalem Media and Communications Centre (JMCC) poll found.

The survey also revealed a softening of support for rocket attacks launched from the Gaza Strip into Israel. In December, shortly after a peace deal brokered by Egypt and advertised as a sweeping victory by Hamas, support for such attacks stood at 74 percent. In the March poll, it slumped to 38.4 percent.

Support for Hamas has decreased significantly - from 28.2 percent in December to 20.6 percent in March - a figure closer to support the movement enjoyed in past polls.

Just over 80 percent support non-violent means of resistance and a clear majority of 60.2 percent consider that military operations harm the Palestinian national interests.

Hamas and Fatah are about to revive reconciliation talks in Cairo. Palestinian Authority president Mahmoud Abbas and Hamas leader Khaled Mashaal are scheduled to meet to discuss forming a unity government and holding presidential and parliamentary elections in the occupied West Bank and Gaza.

A recent report by New York-based Human Rights Watch (HRW) has slammed Hamas for failing to investigate the killings of seven Palestinians accused of collaborating with Israel. The case sparked public outrage during the eight-day conflict in November as the men were shot in public and the body of one was dragged by a motorcycle through the streets.

"Hamas's inability or unwillingness to investigate the brazen murders of seven men makes a mockery of its claims that it's upholding the rule of law in Gaza," said Sarah Whitson, Middle East director of HRW.

"Even before the killings, the abuses the men suffered made the criminal justice system a travesty, regardless of their guilt or innocence."