* New storm lashes Irrawaddy delta
* Military government insists aid effort working well
* EU's top aid official warns time is running out
* Dead and missing could be more than 200,000 (Adds cholera cases, British estimate of dead and missing)
By Aung Hla Tun
YANGON, May 16 (Reuters) - Torrential tropical downpours lashed Myanmar's Irrawaddy delta on Friday, deepening the misery of an estimated 2.5 million destitute survivors of Cyclone Nargis and further hampering the military government's aid efforts.
Despite the latest storm, which is likely to turn already damaged roads to mud in the swamp-covered region, the former Burma's ruling generals insist their relief operations are running smoothly.
However, they issued an edict in state-run newspapers on Friday saying legal action would be taken against anybody found hoarding or selling relief supplies, amid rumours of local military units expropriating trucks of food, blankets and water.
If emergency supplies do not get through in much greater quantities, foreign governments and aid groups say starvation and disease are very real threats.
Some cholera has been confirmed among survivors, but the number was in line with case levels in previous years in Myanmar, the World Health Organization (WHO) said on Friday.
"We don't have an explosion of cholera," Maureen Birmingham, acting WHO representative in Thailand, told reporters in Bangkok.
Diarrhoea, dysentery and skin infections have afflicted some cyclone refugees crammed into monasteries, schools and other temporary shelters after the devastating May 2 storm.
The WHO, which has sent health kits, bleach and chlorine tablets to treat dirty water, said the peak threat from disease was 10 days to one month after a natural disaster.
EU URGES OPENING UP TO AID
The European Union's top aid official, Louis Michel, met ministers in Yangon on Thursday and urged them to admit foreign aid workers and essential equipment to keep the death toll, which the Red Cross says could be as high as 128,000, from rising.
Myanmar state television raised its official death toll on Thursday to 43,328. Independent experts say the figures are probably far higher, with British officials saying the number of dead and missing may be 200,000.
Michel's trip, like so many others before, yielded no results.
"Relations between Myanmar and the international community are difficult," he told Reuters. "But that is not my problem. The time is not for political discussion. It's time to deliver aid to save lives."
Earlier, the reclusive generals, the latest face of 46 years of unbroken military rule, signalled they would not budge on their position of limiting foreign access to the delta, fearful to do so might loosen their vice-like grip on power.
"We have already finished our first phase of emergency relief. We are going onto the second phase, the rebuilding stage," state television quoted Prime Minister Thein Sein as telling his Thai counterpart this week.
Underlining where its main attentions lie, the junta announced an overwhelming vote in favour of an army-backed constitution in a referendum held on May 10 despite calls for a delay in the light of the disaster.
DRIBS AND DRABS
Two weeks after the storm tore through the heavily populated Irrawaddy delta rice bowl, food, medicine and temporary shelter have been sent in dribs and drabs to devastated communities.
In the delta town of Bogalay, where around 10,000 people are thought to have died, people complained of forced labour and low supplies of food at state-run refugee centres.
"They have to break stones at the construction sites. They are paid K1,000 ($1) per day but are not provided any food," said Ko Hla Min, who lost nine family members in the storm.
Along the river in Bogalay rotting corpses were tangled in the scrub. Villagers fished, washed and bathed in the same river.
The United Nations says more than half a million people may now be in temporary settlements.
Despite calls to postpone its constitutional referendum, the junta went ahead in areas not hit by the cyclone.
According to official results, turnout was above 99 percent and more than 92 percent approval of the charter, which gives the army a quarter of all seats in parliament, control of key ministries and the right to suspend the constitution at will.
The charter is a key step in the junta's "roadmap to democracy", but critics dismiss it as an attempt to legitimise the generals' grip on power.
"This referendum was full of cheating and fraud across the country," said Nyan Win, a spokesman for the opposition National League for Democracy. (With additional reporting by Ed Cropley in BANGKOK; Editing by Alex Richardson and Jerry Norton) (For more stories on Myanmar cyclone click on [nSP152717] or follow the link to Reuters AlertNet www.alertnet.org)