I would put it like this. I had the great advantage of having a very long apprenticeship. I came in, in 1984. I didn't become PM until 2004. I had 20 years to master the responsibilities, and to become known to MPs and Singaporeans, so there is no surprise at the end of the day.

Goh Chok Tong also had a very long period, not quite so long but 14 years. He came in in 1976. He took over in 1990.

Ideally, my successor should also have a long period to establish himself and then to take over when he's still quite young, so he has that vigour and that runway to do a good job for two terms, 2-1/2 terms, before he hands over to his successor.

I cannot decide who that person will be. And I cannot say the next PM must be like the last PM. Mr Goh was not like the Minister Mentor. I'm not like Mr Goh. And my successor will not be like me.

Among the ministers and the potential leaders in that generation, they have to work out among themselves their own team dynamics, find somebody they can support, have confidence in and whom Singaporeans will accept as their leader. They must take charge of the country as a team and be responsible for Singapore.

So my job is to make sure there's as strong a team as possible. A Cabinet which is capable, and then among them, some star players.

I've got some players we brought in, in 2001. Some more came in, in 2006. I'm looking for more, because I still need more.

It's one of the most urgent jobs now because if I start looking for people now and field them in the next election, two elections after that will be 13 years from now. I'm 56, plus 13, it's 69. That is very late. So there's no time to be lost.

We must look for people in their 30s or early 40s now, to prepare for that situation 12, 13 years down the road.

Say I get run over by a bus tomorrow. Yes, among the present ministers, one will take over and the country will go on. But you still have that succession problem two elections from now. How are you going to solve that problem? You can't solve it by saying you accept somebody a little bit older.

We need some people to come in now so in two elections' time, they will be in their early 50s, known to Singaporeans, familiar with the job, able as a team to take charge of the country. And that's why I say we are still urgently looking for people. I said it last year during the debate on ministerial salaries, and it's still true.

I have found some people but we want the best possible team. We want to make sure we've not missed out anybody who could do it but maybe needs a bit more persuading to come in.

I don't think you're looking for another clone of yourself, it's not possible. You're looking for a team of people who have to work out their own dynamics, their own division of responsibilities, their own style of government.

This is a very serious problem because if we don't do this and Singapore goes the way of other countries - where people come with very little experience and suddenly, overnight, you have a team of ministers and a PM who have never been in government before - all sorts of things can go wrong, despite the enthusiasm and the excitement and the freshness.

We need self-renewal because if you don't have fresh faces, eventually you don't have that same flow of new ideas, you're not of that new generation which is coming of age in the society.

At the same time, you must have the older, more experienced ones and continually roll over but roll forward, and in the process, generate DPMs (deputy prime ministers) and PMs ever so often.

It's not automatic. You cannot foreordain this. It depends on what the generation is like and where your talent has gone - is it here, is it overseas, has it taken paths which will lead eventually to entering public office, or have they become very successful but really no longer likely to make ministers?

I was looking at some data of our top students to see what happens to them. Take the people with four As at the A levels. We have about 600 or more a year. About two-thirds study in Singapore, and one-third go overseas. One-third is 200, roughly.

Of the people who go overseas, a bit less than half go on scholarship. A bit more than half go on their own. So at least 100 don't go on scholarship. Of these, nearly half have not come back. That doesn't mean they have emigrated; it means they are working abroad. They may be with a merchant bank, they may be with some MNC, they may be pursuing their careers as lawyers or engineers in New York or London. So that's 50 to 60 persons a year gone overseas from among our best and brightest.

Even among the two-thirds - 400 - who studied in Singapore, about 100 of them, we think, are working overseas. So that's 150 or more people from among our 600 top students per year not in circulation - one-quarter of them.

Now hopefully, one day most will come back, and maybe one day after they've come back, they can be identified and channelled and brought into politics. But you can't be certain of that, and this flow is going to continue. So it's a big challenge to find successors, particularly for politics. So that's why we're still looking.

The priority is to develop a next team of ministers from whom we can have the top leadership of not just ministers to look after each of their ministries but the top leadership of the country, DPMs and PM.

We have good people. We need a mix of backgrounds and experiences, which to some extent we have achieved in the last election of 2006 and before that, 2001 - some from the public sector, one or two from the private sector, one or two from the professions.

This time we got in Shanmugam, who's been in the private sector as a top lawyer for a long time.

I would like to give them enough time so they will be ready when I put them into ministries. I need strong ministers in all the ministries, because it's no longer like, say, in the 1970s and maybe 1980s, when you could have a few heavyweight ministries making most of the important decisions and all the rest of your ministries just run the routine matters.

Now each ministry has a significant portfolio and responsibility: If you're doing public transport, you're responding to public concerns all the time; if you're doing the Ministry of Information, Communications and the Arts, you're dealing with a very rapidly changing media as well as technology scene; and if you're doing National Development, you're housing the whole population. If you're running the Ministry of Community Development, Youth and Sports, developing our social safety nets, not to mention preparing for the Youth Olympic Games (YOG) - each one of these is a big responsibility.

Boon Yang wants to step down mid-term. In fact, he spoke to me again this time, but I asked him to stay on for another year so I have a bit more time to expose ministers and try them out before committing to a successor.

Boon Yang is staying on for another year. So in a year's time, we will decide what we will do.

I want to create space in Mica so Lui Tuck Yew, as SMS there, will have the full range of responsibilities under Lee Boon Yang. Vivian is looking after MCYS, and YOG is coming. I cannot spare him out of MCYS.

I have the opportunity to give them a little more exposure first. They've come in, each one successful in his or her own careers. They've learnt quickly on the job but there's a lot to learn on the job. If I can have another year before I put them into the hot seat, that's better.

I want to give them a chance to develop, to find their feet, to be more established with the MPs and with the public, so when I put them in, it's not a shock for either side.

I try to make the gear shifts without jerking. Maybe it's not so exciting for spectators, but I think it's better to do it like that.

I need a mix of people with experience and people who bring in fresh ideas. Everybody who's in the Cabinet has a role to play, from MM all the way down to the new members who have come in, in the last election.

You take Jayakumar. He will no longer be Law Minister but he's still going to be handling foreign policy issues between ministries and foreign policy issues with legal implications. These are matters with very long histories. You can come in with all the ability in the world but unless you have that background and that experience handling it, you won't have the feel and the understanding overnight. You need years to develop this.

Well, the numbers have increased, because the responsibilities have grown, but we have very rarely added new ministries.

There is more work, but we are keeping our team trim. I'm not in a position where I have more talent than I need. If I did, it would be a happy problem.

As for the ageing of the Cabinet, the problem is not when the ministers take over. The problem is how young I'm able to bring them in as office holders. If you look at the office holders who came in, in 2006, they were already all in their 40s - Iswaran, Lui Tuck Yew, Grace Fu.

When I came in, in 1984, my cohort - Wong Kan Seng, Yeo Cheow Tong, Lee Boon Yang - were all in our 30s and we did not consider ourselves particularly young.

This change is a result of society becoming older: The workforce is older, and people rise in their careers more slowly now. The organisations are more established. So when you're in your 30s, you're not in as senior a position and not as well tested or as well known or as well accepted.

I am trying harder to find people in their 30s to bring in. But when they come in, it is harder for them than it used to be: harder to get accepted, harder to fit in.

And so I find the average age of ministers has gone up. It's a plus and a minus. The plus is, by the time they come in, they are more mature, you know them better. But the minus is, you have fewer years to develop them and make them ministers, because if you come in at 30, you can spend five, 10 years before becoming a minister, and it's okay because you're still in your 40s, still vigorous. If you're coming in at 45 and take 10 years before you become a minister, you're past 55 already.

Wong Kan Seng has been repeatedly reminding me, just as Jayakumar has - he says: 'I've been in the Ministry of Home Affairs for 14 years.' I do not yet have a replacement for him in MHA. It's a critical job, both because of the terrorism problem as well as because of law and order and a whole range of things which Home Affairs is looking after. Plus he's also looking after population policy at the national level. He's a vital person and a core member of my team.

As SM Goh said, it's a matter of time. I'm confident it will happen. It hasn't yet taken place, but it will happen.

Yes, there will be further changes before the next election.