A nation-wide 24-hour general strike called by major trade unions on Tuesday could cripple the country's transport, banking and postal systems after the government's attempts to avert it remained unsuccessful on Monday.

Prime Minister Manmohan Singh had appealed to all the major trade unions and 5,000 unaffiliated unions to call off the strike. But the unions rejected the appeal as it came only 48 hours before one of the largest strike calls in the history of independent India.

However, a section of the unions appeared to back off. The Indian National Trade Union Congress (INTUC) said it would not be participating in the strike.

"The strike is politically motivated and illegal. We will oppose it tomorrow (Tuesday)," Ashok Choudhary, national president of INTUC, said. The INTUC is backed by the Congress party.

Unions linked to other coalition partners of the United Progressive Alliance government, including the one affiliated to Mamata Banerjee's Trinamool Congress -- Indian National Trinamool Trade Union Congress, will also not be participating.

Others, who oppose the country-wide strike call are the ones affiliated to the Nationalist Congress Party (NCP) and the Dravida Munnettra Kazhagam (DMK).

It seems political considerations have prevailed over their earlier decision to go on strike.

The trade union are demanding an universal social security net for all unorganised sector workers through creation of a national social security fund, enforcement of basic labour laws and stringent punitive action against violation of labour laws.

Other demands in the charter of the trade unions demands amendment to the Minimum Wages Act, provision for pensions, abolition of contract-based appointments and for putting an end to the disinvestment process of profit-making public sector undertakings (PSUs).

Major sectors like banking, transport, postal and port operations are likely to take a massive hit due to the strike. Key industries such as steel and power may see a low turnout at factories.

The country's largest lender, the State Bank of India, has informed the Bombay Stock Exchange (BSE) that its operations would be affected due to the strike.

In the transport sector, national carrier Air India told IANS that its operations would not be affected due to the strike, as its unions have not given any notice to the management.

The Indian Railways have said its operations will be normal. But it is widely expected that rail tracks may be blocked affecting services. Also road traffic on national, state highways could be hit as various unions are known to target these.

States like Kerala, Tripura and West Bengal, where the communist parties have a greater hold, are likely to be affected the most.

The government has been asking the unions to desist from going for the industrial action by trying to reach out to them through open advertisements issued by the labour ministry in leading national dailies.

"Most of the issues relating to labour raised by the central trade unions have already been addressed to a substantial extent. However, I do assure all of them that I am always open to discussion on any of the issues relating to labour at any time and resolve the same amicably through consultations," union Labour Minister Mallikarjun Kharge said in an open appeal published in leading national dailies.