The Bulgarian Government has intervened to provide a state aircraft to fly home Russian tourists stranded at the airport in the Black Sea city of Bourgas after flights were cancelled because of a debt dispute between Bulgaria Air and tour operator Alma Tour.

On September 10, talks between Bulgaria Air and Alma Tour on resolving their dispute about the tour operator’s seven million leva (about 3.5 million euro) debt to the airline, Bulgaria’s national flag carrier, failed. The previous day, Bulgaria Air's decision to cancel flights booked by and through Alma Tour left an estimated 800 tourists, mostly from Russia, stranded.

Bulgarian Prime Minister Boiko Borissov and Transport Minister Ivailo Moskovski both have warned that Bulgaria Air and Alma Tour could lose their licences because of the standoff that left hundreds of Russian tourists stranded.

The standoff affected not only charter and other flights to St Petersburg and Moscow but also incoming flights bringing Russian late-season holidaymakers to Bulgaria.

Bulgarian National Radio said that a flight from Saint Petersburg to Bulgaria, which was planned for September 9, was cancelled. The would-be passengers had bought a holiday in Bulgaria through Alma Tour.

According to an Alma Tour staff member in Saint Petersburg, most of the customers were transported by other airline companies while some people were still waiting at the airport.

The Sofia City Prosecutor’s Office was investigating whether there had been any wrongdoing by Alma Tour, Bulgarian National Television (BNT) said.

A batch of just more than 180 Russian tourists was transported to Moscow on a Bulgaria Air special flight that left about 7pm Bulgaria time on September 10, paid for a Russian tour operator.

A Government 92-seat aircraft carrying more Russian nationals was scheduled to leave at about 8pm from Bulgaria. The flight was to transport people who were ill, elderly people, children and pregnant women.

As the subsequently-failed talks proceeded during the day on September 10, Moskovski said that if they failed, the Government would intervene to transport the tourists – but that both the airline and tour operator would face serious penalties, including loss of their licences.

Borissov was adamant that the two parties in the dispute could face confiscation of their licences.

Acting on the instructions of Borissov, teams from three ministries were working to resolve the problem of Russian travellers stranded at Bourgas Airport, a statement issued by the Foreign Ministry said earlier on September 10.

The ministries were those of Transport and Communications, Economy and Energy and Foreign Affairs.

A Foreign Ministry team was working on dealing with the situation arising from the fact that the visas of some of the foreign nationals had expired.

Bulgarian media said that those affected were not only Russian citizens but other foreign nationals too, including citizens of Finland.

Three hundred of the Russians spent the night at Bourgas hotels, local media said.

In a statement, Alma Tour's board of directors apologised for the cancelled flights that had created a "very unpleasant situation" for its customers.

"We express our deep regret that a commercial row has created so much inconvenience to Bulgaria’s tourists and guests. We do hope that despite the surprising circumstances we faced, the commercial disagreements will be overcome through talks with Bulgaria Air and the necessary compromise will be reached so that both the charter flights and tourist program could be fulfilled," the tour operator said.

Alma Tour expressed its willingness to find a solution as soon as possible together with Bulgaria Air and Bulgaria’s state and municipal authorities.

BNT reported that Bulgaria's tourism industry was worried about the impact of the episode on the industry.