Trade unions across the country today began a five-day coal industry strike, which is likely to affect production of up to 1.5 million tonnes a day and fuel supply to power plants.The strike call, for the biggest industrial action for any sector since 1977, has been given by the five leading trade unions of the country including BJP-backed Bharatiya Mazdoor Sangh (BMS).They are protesting against 'disinvestment and restructuring of state-run Coal India' and to press for their other demands including the roll-back of what they call as "process of denationalising of coal sector".The strike can affect coal production of up to 1.5 million tonnes a day and may also hit supplies to power plants which are already grappling with fuel shortages."We are hopeful the situation would be resolved in an amicable manner. The precise impact of the strike would be known later and it would be premature to predict (the impact) at this juncture," Coal India's newly appointed chairman Sutirtha Bhattacharya told PTI."It is true that production picks up tempo in the last quarter, as the closure of fiscal draws near. It is unfortunate that the unions have called for the strike. We have appealed to them to withdraw the strike in the national interest and even now our efforts are on to persuade them to refrain from going to strike," he said.While All India Coal Workers Federation leader Jibon Roy said in a statement that about seven lakh workers have joined the strike, the government has also called a meeting with representatives of major trade unions - BMS, INTUC, AITUC, CITU and HMS -- to sort out the issue.The trade unions have boycotted the earlier two meetings called by the government."The workers across the nation have proceeded on strike," Indian National Mineworkers' Federation (INMF) Secretary General S Q Zama said, while adding that the strike began from the first shift starting 6 am today."Almost 100 per cent of Coal India (CIL) workers are participating in the agitation. Only handful of emergency services are continuing," he said, while adding that around 70-80 per cent of SCCL ( Singareni Collieries Company Ltd ) workers are also protesting.A Coal India official said "there is picketing outside CIL headquarters in Kolkata as of now."The protest comes at a time when the power plants across the country are grappling with fuel shortages.Coal India Ltd had earlier said that it has already stepped up supplies of the power plants, which have been facing fuel shortages, to tide over the likely disruption of supplies due to the strike."CIL is suppling extra volumes of coal to the power plants and the Railways is fully cooperating with the coal PSU," an official had said yesterday.CIL, which accounts for over 80 per cent of domestic coal production, has a workforce of over 3 lakh.All five major trade unions of the coal PSU had boycotted a meeting called by Coal Minister Piyush Goyal last week.Meanwhile, electricity workers union EEFI has also extended its support to the strike call.