HELSINKI, Feb 1 (Reuters) - Some 290,000 Finnish workers began two days of strike action on Thursday to protest against the right-wing government's planned labour market reforms and proposed cuts to social welfare.

Companies and labour unions said the strikes were expected to halt much of Finland's air traffic, hit oil refinery output and close many shops, factories and kindergartens.

"The government's plan is cold-blooded. First, the right to strike will be severely restricted and then tough cuts are pushed through," Jarkko Eloranta, president of Finland's largest trade union association SAK, told Reuters.

In recent months, labour unions have protested against government plans to favour local work agreements over centralised accords, limit the right to strike, make it easier to terminate work contracts and cut unemployment benefits.

The unions have said they are up for a long fight if needed, threatening to follow up with more strikes if the government, which took office last year, does not back down.

The government has stayed the course, however, arguing that Finland needs to boost productivity and cut its fiscal deficit.

Employment Minister Arto Satonen told Reuters he found the widespread strikes regrettable but said the government's plans were vital to the future of Finland's welfare system.

"We need to make structural reforms to raise the employment rate," he said, adding the strikes would be costly.

"One can disagree with the government's policies and protest against the government, but the strikes target the employers, the people who pay the wages," Satonen said.

Top industry lobby group EK and the government have said the changes are needed to bring the Nordic country's economy on par with comparable states such as neighbouring Sweden.

"Reforms are necessary and the unions have not offered any alternatives for correcting our alarming economic situation," EK chief executive Jyri Hakamies said in a statement.

The striking workers comprise 13% of the 2.29 million people employed in Finland, according to official statistics from 2023.

Finnish flag carrier Finnair said on Monday it would cancel some 550 flights due to the strike, while fuel producer Neste's Porvoo refinery will supply less petrol and diesel for approximately a week. (Reporting by Essi Lehto; editing by Terje Solsvik, Anne Kauranen, Kylie MacLellan and Mark Heinrich)