Key Finnish politicians have been warned that Russia could halt its gas supplies to neighbouring Finland on Friday, local newspaper Iltalehti reported on Thursday, citing unnamed sources.
Finland's President Sauli Niinisto and Prime Minister Sanna Marin on Thursday said Finland would apply to join the Western defence alliance NATO "without delay", prompting Russia to vow a response.
The majority of gas used in Finland comes from Russia but gas only accounts for some 5% of the country's annual energy consumption.
However losing most of the gas supply would mean industry giants like Neste and Metsa and also other companies in forestry, chemical and food industries would need to find alternative energy sources or adapt their production.
On May 5, the Finnish government said it was prepared for the possibility of its eastern neighbour cutting off gas delivery in late May as a response to Finland's refusal to abide by Russian demands for gas payments to be made in roubles.
With direct pipeline connections with Russia, Finland and the Baltics are more reliant on Russian gas than other European countries. If Russian gas supply is reduced or cut, Finland, Estonia, Latvia and Lithuania might have to curtail demand, European gas operator network ENTSOG said in their summer outlook in April.