Israel's centre-left opposition leader Shimon Peres has agreed to work with right-wing Prime Minister Ariel Sharon to push forward a unilateral plan to withdraw from the occupied Gaza Strip. The two met on Monday to discuss forming a national unity government, but both leaders are expected to hold more meetings with their own supporters before negotiations start on forging a coalition. A broad-based coalition government with Labour would give Sharon much-needed support as he pushes forward with his contentious plan to withdraw from the Gaza Strip. But Sharon also risks alienating hard-liners within his Likud party who oppose a union with the opposition. The prime minister warned opposing members of his ruling coalition he could call early elections if they blocked his bid to widen his government to push ahead with the Gaza pullout plan. **West Bank control?*** Palestinians fear the planned Gaza pullout will consolidate Israel's occupation of the West Bank. Sharon's "disengagement plan" envisions dismantling all 21 Gaza Jewish settlements - illegal under international law - and four of 120 in the West Bank by 2005. The two sides agreed on supporting the Gaza plan, said a senior political source. "But it was still only the very beginning of negotiation and they did not discuss specific issues. Peres said he still has to get his party's mandate if Labour is to join a government," the source said. Israel's cabinet approved the withdrawal project after Sharon fired two far-right ministers, but that cost the former general the majority in parliament he will need next year if he is to push through the phases of the plan. **PHOTO CAPTION*** Sharon (L) and Peres are long-time political rivals. (Al-Jazeera)