BERLIN/PRAGUE/WARSAW (BLOOMBERG) - As Russia's invasion prompts the exodus of more than a million people from Ukraine, a smaller group is moving the other way. Growing in number by the day, they're off to war.

Whether builders, warehouse workers or truck drivers, a flow of mainly Ukrainian men are headed east from nearby countries where hundreds of thousands of them and their families have settled in recent years. Almost 80,000 have made the trip home since the Kremlin-ordered assault began on Feb 24, Ukraine's State Border Guard Service said this week. The returnees are back to join the military or the territorial defence forces, it said, as the country's cities face the Russian barrage.

Sergey Lunga, who's worked for three years in a warehouse outside of Prague, said he was returning to his home in western Ukraine near the border with Romania. His employer didn't protest, he said, and promised him his job back, no matter how long he's away. "I will see what is going on there and if they need me," Lunga, 51, said in an interview at the Florenc bus station in the center of the Czech capital, standing with a group of men and a family waiting to embark for the east. "But I will only know when I get home."

While many employers express sympathy with the urge among Ukrainian fighting-aged men to return, their absence will leave a hole in eastern European nations where they make up a significant chunk of the workforce, especially in industries like transport and construction.

In Poland, the largest economy in eastern Europe, more than a million Ukrainians settled in the country over the eight years since Russia's occupation of Crimea from Ukraine. Many filled jobs left by Poles who themselves ventured west for work after the country's 2004 accession into the EU.

Economic Impact

Those workers are a backbone of some key industries. A 2020 central bank report even estimated that Ukrainian workers contributed a half percentage point to economic growth every year between 2014 and 2018. Poland's biggest trucker association, the Warsaw-based Association of International Road Carriers, estimates that about a third of its drivers working routes outside the country are from Ukraine. Between a quarter and 30 per cent of Ukrainian drivers working in Polish transport companies have requested a leave of absence to return to fight, according to Maciej Wronski, head of the Association of Transport and Logistics company. "The situation is becoming very serious," Wronski said, adding that the shortage exacerbates the industry's struggle with high fuel costs and European Union regulations. "We are now facing logistic curbs that may have an additional impact on the European economy."

The Polish property developers association estimated that between 20 per cent and 30 per cent of Ukrainian workers left construction sites since the invasion began.

In the Czech Republic, some 200,000 Ukrainians are officially registered in the country, according to the Czech Chamber of Commerce. Some firms have already expressed concern about a possible outflow of workers. Metrostav, the Czech Republic's biggest construction company, has subcontractors that employ hundreds of Ukrainians, making the industry vulnerable to shortages. A large number of departing workers could affect projects across the country, according to Metrostav spokesman Vojtech Kostiha. "We sort of believe it's actually Ukrainians that help build everything that's done here," Kostiha said.

Budimex, Poland's biggest builder, has offered to pay salaries even after Ukrainian workers exhaust paid leave, calling on subcontractors to do the same. "We want to support them and get them back, hopefully," Budimex spokesman Michal Wrzosek said.

Local media has reported buses leaving Polish cities fully booked with young Ukrainians heading back, laden with medicine, food and clothing. Poland's biggest pharmaceutical distributor, Neuca, already sees elevated demand and requests for medical supplies.

While waiting for the bus in Prague, Lunga said he enjoyed his work in the warehouse, but had no real choice about whether to go back. His home, in Chernivtsi Oblast, is as yet untouched by the fighting. "Everything is fine there, but I got a call from my teenage daughter overnight and I knew I had to leave," he said, breaking into tears. "My mother is also there."

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