This is despite the reforms being major and complicating, he told trade unionists and members at the NTUC National Delegates conference on Monday.

The changes 'are not easy for people to understand', said PM Lee who announced a series of reforms to the CPF system in his National Day Rally speech in August.

These changes include an extra one percentage point interest for the first $60,000 in the CPF accounts, a delayed draw-down age of the Minimum Sum from 62 to 65, and a new compulsory annuity scheme.

To help people understand the CPF changes, a series of initiatives has been launched.

Said Mr Lee on Monday: 'We had to make a special effort to reach out to the public - forums, dialogues, feedback sessions, videos, cartoons, CD-ROMs, all sorts of ways to get the message across, some serious, some not so serious. And I think from the reactions so far, the message is getting through.'

At the same time, the labour movement has been crucial in helping to get the support of the workers.

'I have the strong support of the labour movement, because they understand our challenges and our longer-term interests, because they have worked hard championing the cause of workers, persuade them to support policies which bring long-term benefits to themselves,' he said.

He added that he had sought the union leaders' input before announcing the CPF changes in his National Day Rally speech - so that 'there were no surprises'.

'I met some of them to discuss the ideas, and test out their reactions, to pick their brains, how they saw it, how they could improve on our proposals. They gave me good advice and they helped to shape both the substance and the presentation of the policies,' he said.

The basic message for the CPF changes is 'a simple one', boiling down to three parts, said Mr Lee.

First, Singaporeans will have to work longer, as they are living longer. Higher Workfare has encouraged older workers to work, and companies to hire them, he said.

'And I think it's also possible because we've been educating the employers, and they now understand better that it is in their interests to employ older workers and treat them fairly.'

Second, the change is aimed at helping CPF members to earn more on their savings - 'not by taking risks or getting excited on the stock market, but by government paying more interest... to help workers save more for their old age'.

Third, drawing down savings later will help make them stretch longer 'so that when you're old you have something to take care of you and you will not run out of CPF monies before you grow old'.

The National Longevity Insurance Committee, chaired by Professor Lim Pin, is working out the details of the longevity insurance scheme.

Mr Lee also noted that there are three union leaders on the committee: Mr Seng Han Thong, Mr Terry Lee and Mr G Rajendran.

'They understand the issues and I am sure that they will help the committee to arrive at good recommendations,' he said.