By Tsvetelia Tsolova

SOFIA (Reuters) - Nearly 10 years after Bulgaria joined the European Union, many of its people feel their problems are too low down the priority list in Brussels.

Many disappointed Bulgarians are now looking toward Russia, their former overlord in the Soviet era, as a more relevant neighbor.

That sentiment is likely to be reinforced in a presidential election run-off on Sunday which former air force commander General Rumen Radev, who is friendly toward the Kremlin, is expected to win.

Radev's position that Bulgaria, a NATO member, should hedge its bets when it comes to international alliances, has hit a nerve in the Black Sea state, which already depends on Russia for most of its energy, military equipment and tourism revenues.

"The West and the European Union committed many mistakes with Russia in recent years," said Emilia Trencheva, a 48-year old accountant who was enjoying a walk in the gardens of the 1907 National Theatre in Sofia,a popular leisure spot.

"Russia is very important and they isolated it. Rumen Radev will find the right balance. He promised security and this is what people want to hear," she said

Since it annexed Crimea in 2014, Moscow has held military exercises and conducted overflights throughout what was once Communist-ruled Southeast Europe. It has also mounted a lobbying campaign for influence, diplomats say.

Radev, who resigned from the air force to stand in the election as an independent allied to the Socialist Party, has expressed tolerance for the Russian move in Ukraine and favors easing Western sanctions on Moscow.

"Of course there are violations of international law in Crimea," he told BTV television after winning the election first round on Sunday. "But it is also a fact that at the moment, a Russian flag is flying over Crimea. What should we do? Close our eyes?"

Bulgaria's relationship with its communist-era masters contrasts with much of the former Soviet bloc, which saw Moscow as an occupier, not a friend.

Bulgarians share a similar language and the Cyrillic alphabet with Russians. They also feel historical gratitude after Russia liberated Bulgaria from 500 years of Ottoman rule in late 19th century.

Unlike Hungary, Czechoslovakia or Poland, Bulgarians did not see Russian military force used against them and many did not develop a deep resentment to Russians.

Loyalties were put aside when the country of 7.2 million people joined the EU in 2007, with many hoping Brussels technocrats would force corrupt politicians to clean up and help them revive a struggling economy.

But Bulgaria remains the EU's poorest member. Popular anger over poor progress in eradicating graft and crime boiled over in 2014 into street protests, putting in power the current center-right government of the GERB party.

GERB appears to have disappointed voters as well, many of whom now associate it with the EU's failure to come through with reforms, and see it as corrupt elites.

"We see a collapse of trust in traditional authorities in the European Union," said Parvan Simeonov, a political analyst with Gallup International in Sofia.

"Only a few years ago, it was unthinkable to hear criticism of Western governments. This is no longer the case. The EU no longer fulfils the hopes of many people."

A Gallup poll conducted in June showed trust in the EU has dropped to its lowest level since 2007 at 48 percent, from about 60 percent. Another pollster said in August that 51 percent of Bulgarians have a strong positive attitude toward Russia.

Gallup listed the EU's internal problems such as the prospects of Brexit, its confrontation with Russia, the migrant crisis and the threat of terrorism among issues that worried voters.

Radev's calls have resonated elsewhere in the region.

In Moldova, pro-Russia Socialist Igor Dodon, 41, is expected to win another presidential vote on Sunday after campaigning on a pledge to reverse the country's course toward EU integration.

Serbia, where Moscow controls the oil and gas sector, is hosting a joint military exercise with Russia dubbed "Slavic Brotherhood". The pro-EU prime minister of its former Yugoslav peer Montenegro lost his parliamentary majority in an October election.

Bulgaria has built a fence to protect its border with Turkey to keep out migrants and refugees. Many Bulgarians fear that Muslim refugees pose a threat to their predominantly Orthodox Christian culture, and increase the risk for terrorist attacks and radicalizing its Muslim minority.

"I will vote for Radev on Sunday because as he said, I don't want Bulgaria to become a migrant ghetto," said Boris Krastev, a 58-year-old scientist.

ENTWINED

The two countries are already entwined in several ways.

Economic sanctions against Russia are opposed by nearly half of Bulgarians, who fear backing them would put Bulgaria at a disadvantage in other economic projects with Russia.

The sanctions had an impact on tourism, which has shrunk sharply. Some 700,000 Russians visited Bulgaria in 2013 compared with less than 500,000 last year.

The trend was overturned this summer when Russian holidaymakers came back. Prime Minister Boiko Borisov said this was a result of his dialogue with Russian President Vladimir Putin.

Bulgaria is almost completely reliant on Russian gas supplies. Its only oil refinery is controlled by Russia's LUKOIL. Its nuclear power plant, which produces about 35 percent of the electricity in the country, operates on Soviet-built reactors and Russian nuclear fuel.

A study by Centre for Strategic and International Studies in Washington and the Sofia-based Center for the Study for the Democracy, released in October, said that Russia's economic presence is so strong that Bulgaria is "at high risk of Russian-influenced state capture".

The study, entitled "The Kremlin Playbook", said that due to its strong economic footprint, averaging 22 percent of GDP between 2015 and 2014, Russia was able to cultivate relationships with corrupt businessmen and local oligarchs who in turn have influence on politicians.

Meanwhile exports to Russia have dropped 24 percent last year alone, while imports to Bulgaria fell 20 percent, trade figures show.

"Should there be an instance where the European Union or NATO request that Sofia takes steps that are perceived to work against Russia's interests, the Bulgarian government would come under enormous pressure from pro-Russian parties, prominent businessmen and organizations that mobilize a full range of tools to change the policy in Moscow's favor," it said.

    Foreign Minister Daniel Mitov said that if Radev wins the election, Bulgaria could fall foul of the EU because he sided with the Russian view on Crimea.

"I guarantee you that if Mr Radev expresses such a position at any meeting of head of states, the next stage will be a full isolation of Bulgaria," he said.

(additional reporting by Angel Krasimirov in Sofia and Ivana Sekularac in Belgrade; writing by Justyna Pawlak, editing by Angus MacSwan)