Even as aid agencies struggle to meet the immediate needs of those left injured, homeless and traumatised by the Israeli operation in Gaza, concerns are growing that reconstruction efforts could become bogged down in a complex political tangle. Initial Palestinian estimates said rebuilding would cost $2bn (£1.4bn) and take three to five years, even without the host of obstacles Gaza faces. [...] UN relief agency Unrwa says it has contacts with Hamas "even at ministerial level", but strictly on technical issues related to the delivery of its humanitarian services in line with wider UN policy. And the distribution of some World Food Programme aid is carried out by Hamas - albeit with strict monitoring in place to ensure it reaches the people it is intended for. "In every country that we work in, we deal with the authorities - so in Gaza we deal with the Ministry of Social Affairs. "If the next question is 'Are they Hamas?', then the answer is 'Yes they are'," says spokesman Robin Lodge.