(Corrects month to "May" in second paragraph under "POLITICAL PRESSURE" subhead)
* EU's top aid official in Yangon for talks
* U.N. proposes high-level pledging conference for Myanmar
* Estimate of numbers affected raised to 2.5 million
* Junta says overwhelming post-cyclone vote for constitution (Updates with vote on charter, adds official casualty figures)
By Aung Hla Tun
YANGON, May 15 (Reuters) - Western powers kept up the pressure on Myanmar's generals on Thursday to allow a massive aid effort as relief workers struggled to help an estimated 2.5 million people left destitute by Cyclone Nargis.
The European Union's top aid official has warned that the military government's restrictions on foreign aid workers and equipment were increasing the risk of starvation and disease in the country formerly known as Burma.
Nearly two weeks after the storm tore through the heavily populated Irrawaddy delta rice bowl, leaving up to 128,000 people dead, supplies of food, medicine and temporary shelter have been sent in dribs and drabs to devastated communities.
Monasteries and schools are sheltering the homeless and refugees are clamouring to get into these privately run centres rather than government-run camps.
In the delta town of Bogalay, where around 10,000 people are thought to have perished, people complain of forced labour and low supplies of food at the state-run 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 members of his family in the storm.
Along the river in Bogalay rotting corpses are still tangled in the scrub. Villagers fish, wash and bathe in the same river.
The United Nations has said over half a million people may now be sheltering in temporary settlements.
The United Nations has ramped up its estimate of the number of people in urgent need of aid to 2.5 million, and called for a high-level donors conference to deal with the crisis.
Myanmar state television raised its official toll to 38,491 dead, 1,403 injured and 27,838 missing on Wednesday, but independent experts say the likely figures are far higher.
The devastation had caused some opposition and human rights groups to urge the government to postpone a planned referendum on an army-drafted constitution, a vote they said would be difficult to conduct in the midst of the tragedy.
In the event the junta went ahead on May 10 in areas not seriously affected by the cyclone, and said on Thursday more than 92 percent of the ballots cast were in favour of the charter.
The military sees the constitution as a key step in its seven-stage roadmap to democracy, which critics say will only entrench army rule.
"This referendum was full of cheating and fraud across the country," said Nyan Win, a spokesman for the opposition National League for Democracy.
A vote in the cyclone-hit areas is set for May 24.
The junta has consistently resisted outside calls for faster and more transparent moves to democracy, and since the cyclone has been equally resistant to pressure to open up the country to full-bore foreign aid operations.
Louis Michel, the European Union's top aid official, is in Yangon for talks with the junta a day after Thailand's prime minister was told Myanmar could deal with the problem by itself.
"We want to convince the authorities of our good faith. We are there for humanitarian reasons," Michel told reporters.
He dismissed suggestions from some countries that they should bring in aid without waiting for the authorities' permission.
But as the clock ticks and conditions deteriorate, with monsoon rains adding to the misery and aggravating transportation problems, the political pressure on Myanmar is likely to grow.
Britain's U.N. ambassador, John Sawers, has indicated a high-level conference would be more than a donors' meeting, calling it a "major international meeting" in line with Prime Minister Gordon Brown's calls for a U.N. summit on aid efforts.
PATIENCE WITH GENERALS
However, the Secretary-General of the Association of Southeast Asian nations urged patience.
"We are trying to work around a very, very strict resistance and mentality and mindset that have been there for a long, long time," Surin Pitsuwan, a former Thai foreign minister, told an audience at the Council on Foreign Relations in Washington.
Myanmar's military rulers have repeatedly crushed pro-democracy movements and tightly restrict visits by foreigners, especially journalists.
Officials said despite reports some supplies were being diverted by the army, they would keep making deliveries, while continuing to urge that aid workers be granted visas.
In Bogalay relief materials were being held in storage waiting for distribution and government officials sold tin-sheets for roofs at K4,900 ($5) apiece, far above the budget of most.
Po Aung, 57, who survived the tidal wive that tore through his village by clinging onto a tree, just wants to go home.
"Those dead are gone. But, we the remaining want to return to our own place," said the 57-year old, one of 80 survivors from a village of over 500.
"We are very sad and disappointed too. We just don't know what to do." (Additional reporting by Nopporn Wong-Anan and Darren Schuettler in BANGKOK; Writing by Carmel Crimmins; Editing by Jerry Norton) (For more stories on Myanmar cyclone click on [nSP152717] or follow the link to Reuters AlertNet www.alertnet.org)