* Crimea's prime minister predicts overwhelming "yes" referendum vote
* Says vote will uphold European standards
* Pledges more help for Crimean Tatars
* Says Ukrainian military personnel will be offered safe passage to leave
By Aleksandar Vasovic
SIMFEROPOL, Ukraine, March 13 (Reuters) - The leader of Crimea's separatist authorities said more than 80 percent of the region's people supported the break with Ukraine and union with Russia that they will vote on in a referendum on Sunday.
Sergei Aksyonov, who came to power as Russian-backed forces seized the Black Sea peninsula last week, dismissed opponents' accusations that he will fix the outcome on Moscow's orders.
Now Crimea's prime minister, he told Reuters on Thursday that the plebiscite would deliver a "Yes" vote to accepting Russian sovereignty without recourse to fraud.
"The process will be transparent and fair," he said inside Crimea's regional parliament building. "We guarantee that all aspects of European law will be followed, including security for voters."
Aksyonov, whose election in a closed session of the regional parliament is not recognised in Kiev, said there was no doubt voters would back the first of two options on the ballot paper, preferring an immediate transfer of allegiance to Russia.
"On March 16, a majority of Crimeans will vote for the first option, which is joining the Russian Federation. We have a survey by renowned Ukrainian and Crimean polling experts showing clearly and plainly that more than 80 percent of people in Crimea are ready to join the Russian federation."
Aksyonov, 41, who earned the nickname "Goblin" during his days in business in the chaotic years that followed the collapse of the Soviet Union, dismissed suggestions that he was chosen by the Kremlin to front a military-backed takeover of a territory where a majority of the two million people are ethnic Russians.
"Our relations are friendly and brotherly," he said, adding that he knew many Russian ministers and members of parliament.
He denied there was anything amiss in his own election on Feb. 27 by a Crimean parliament controlled by armed men who did not let journalists enter: "This is a total lie," he said.
He said the assembly members who voted for him were known.
At least one lawmaker who said his vote was registered in favour of Aksyonov has said he was not in the chamber.
Aksyonov also denied Russian troops were involved in blockading Ukrainian forces in their bases in the region, saying the only Russian servicemen in Crimea were with the Black Sea Fleet based there.
The men in unmarked uniforms who were holding Ukrainian troops virtual prisoners, he said, were from local militias.
Aksyonov warned that people in the region were, however, on guard, fearing that provocateurs could wear Russian uniforms to "attack Ukrainian bases and destabilise the situation" - a concern that explained why flights from areas other than Russia had been shut down - "to prevent radicals from coming".
Ukraine's leaders in Kiev, who took power after protests toppled the pro-Moscow president last month, want Crimeans to boycott the referendum - as do leaders of Crimea's ethnic Tatars, some 12 percent of the region's population, who are strongly opposed to rule from Moscow, which long oppressed them.
Aksyonov dismissed concerns among Tatars, who were deported en masse to Central Asia by Stalin during World War Two, and said that once Crimea was part of Russia they would be assured a quota of seats in the regional assembly and have financial aid.
"We have always had constructive dialogue with the Tatars," he said. "Financing for Crimean Tatars will be doubled this year ... It is all calm on the streets. There are no ethnic or religious conflicts and we will never allow that."
For those in Crimea who want to remain Ukrainian, he said: "We are not forcing anyone to get rid of a Ukrainian passport and we will not force anyone to do so. So people can keep them.
"But those who want to get salaries and pensions in line with Russian laws will have to have Russian passports, they must be citizens of Russia. There will not be any pressure on those who do not vote and we will all have same opportunities."
The fate of Ukrainian military personnel in the peninsula, most of whom are long-time local residents, would depend, he said, on whether they were ready to switch allegiance to Russia.
Those who refused would have to leave: "I am giving them guarantees of safe passage out of Crimea ... We are ready to secure a corridor ... All those military units that do not agree to serve on Crimean territory will be given free passage to Ukraine and their security will be guaranteed."
He said 80 percent of troops, many of them local Crimeans, were ready to join local armed forces and accused officers from western Ukraine, the heartland of Ukrainian nationalism, of fuelling tension and refusing to swear loyalty to his government:
"Some soldiers are ready to arrest officers," he said. "But I'm telling them to hang on and wait for the referendum result." (Reporting by Alastair Macdonald; Editing by Ron Popeski)