Thousands of steelworkers will start voting tomorrow on whether to accept reforms to their pensions which will determine the future of Tata's UK operations.
Leaders of three trade unions are recommending acceptance of the changes as the best that can be achieved through negotiation.
The changes include the introduction of a defined contribution (DC) pension scheme, with maximum employer contributions of 10%, following the closure of the British Steel Pension Scheme (BSPS) to future accrual.
The unions said their independent legal and pension advisers, as well as the BSPS Trustees, have advised the scheme has to close to future accrual because it is heading for the Pension Protection Fund - a lifeboat for failing schemes - and the company into insolvency.
The company, which has a pipe mill in Hartlepool, intends to close the BSPS to future accrual on March 31 and introduce a defined contribution pension scheme with maximum employer contributions of 10%, based on employee contributions of 6%.
The company's original proposal was to bring in a defined contribution scheme with contributions of 3% from the employer and 3% from the employee.
A joint union statement to steelworkers said: "We do not make this recommendation lightly. Nobody is saying that the proposal on the table is without issues.
"We fully understand the concerns of members, particularly around the BSPS.
"But as we have said before, what you are voting on is the best outcome that could be achieved through negotiation.
"It is our collective view, supported by our independent experts, that this is the only credible and viable way to secure the future.
"Although this is a situation that we would never have wished for, it is also the only way to protect the benefits you have already accrued and to provide a chance to prevent the BSPS free-falling into the Pension Protection Fund."
The BSPS is one of Britain's largest pension schemes, with 130,000 members.
Tata inherited the scheme when it bought Corus, formerly state-owned British Steel, in 2007.
The Indian conglomerate said last year it would sell its UK business but it has since decided to seek a partner and has been in lengthy talks with German firm ThyssenKrupp.
The pension scheme trustees have warned the current deficit of over £400 million is set to rise to between £1 billion and £2 billion at its next actuarial valuation in March.
Voting on the changes ends in mid February.