Prime Minister Gordon Brown and his predecessor, Tony Blair, made a rare public appearance together Thursday to kick off 24 hours of Middle East diplomacy aimed at spurring investment in the occupied territories. Brown opened the Palestinian Investment Conference by calling for more private sector investment in the West Bank and Gaza Strip. He said such investment was vital for peace. "There is an economic prize before us," Brown said. "There is a real chance to build on the ingenuity and skills of the Palestinian people to build real peace and prosperity in the region." The investors' meeting is being attending mostly by business people who already have some financial interests in the Palestinian territories. However, a meeting of ministers from the so-called Middle East Quartet of peacemakers will take place on the sidelines of the conference. UN Secretary-General Ban Ki-moon will chair that meeting and also meet with foreign ministers from a number of Arab states in an effort to develop economic institutions in the West Bank and Gaza. Foreign Minister Tzipi Livni flew to London Thursday evening to take part in the conference and to hold talks with a number of leaders. Livni, who will deliver an address at the conference, is also scheduled to meet with Brown, his foreign secretary David Miliband, Ban, as well as her Egyptian and Jordanian counterparts. On Friday, three high-level meetings will take place in London under the auspices of the Quartet of the Middle East, the Ad Hoc Liaison Committee for aid to the Palestinian Authority (AHLC) and the E3+3. There will also be a meeting to discuss Iran, which will present an opportunity to send a clear statement to back up the latest UN Security Council resolution and pressure the Islamic Republic ahead of the next IAEA report to the UN Security Council in June. US Secretary of State Condoleezza Rice, Secretary-General of the Council of the European Union Javier Solana, and Miliband are among the confirmed attendees of that meeting. At the conference, Brown called on Israel to lift restrictions on Gaza and on border crossing points to normalize the situation. Blair, now an envoy for the Quartet, followed Brown and Palestinian Authority Prime Minister Salaam Fayad. He urged investors to consider doing business in Palestine, pointing out that many are doing well there despite the obvious obstacles. Blair said many investors were already doing well in the Palestinian territories despite obvious obstacles. "People talk about the problems they see on their TV screens, and we are not minimizing that," said Blair, looking tan and relaxed after a long period out of the public eye. "Yes, there are enormous problems. But the economy on the West Bank is actually growing and people are making money." Despite persistent talk of bad feelings between Brown and Blair, the two shared a podium, praised each other and shook hands at the start of the meeting at a central London hotel. Quartet ministers representing the US, the European Union, the United Nations and Russia are expected to meet on the conference's sidelines. Blair said businessmen considering projects in the West Bank or Gaza should be aware that the Palestinian prime minister has created a pro-business climate with friendly taxation laws. "It is necessary to understand the Palestinian people," he said. "They are people of extraordinary ability and fortitude and they are determined to make this work. There is a lot of good work being done." Blair and Brown both encouraged businessmen to attend an investment conference in Bethlehem on the West Bank later this month. Blair said the Israeli government was making a good faith effort to make it easy for people to attend the conference. After Brown left, investors asked Blair and Fayad questions that focused on logistical challenges of doing business in the West Bank and Gaza. Some said the high cost of broadband service was an impediment; others mentioned the many roadblocks and checkpoints that make the movements of goods difficult. Blair said there were ongoing negotiations with the Israeli government on many points, including the need for more mobile phone competition. He also said there are plans to open the Allenby Bridge between Jordan and the West Bank for longer hours. Jonny Paul contributed to this report.