'You need people with a range of experiences - some from Government, some knowing about business, some having practised in the private sector and some understanding security issues. You want people with a range of backgrounds,' he said.

Getting public sector people has so far 'not been unsuccessful' because of the talent management system in the civil service. 'So you know where to look for them. Perhaps because we have put quite a number of our good people into the public service, so we can use them,' he said.

However, in the private sector, the good people are not only scattered and harder to spot, they also have to undergo a mindset change.

'To make that transition from a private-sector mindset to be a successful lawyer, banker, doctor or businessman, to become a successful political leader running a ministry or cultivating your ground and acquiring that political touch, it's not an easy transition to make,' said Mr Lee.

However, some ministers had successfully made the switch and he cited four.

They are: Mrs Lim Hwee Hua, new Minister in the Prime Minister's Office, who was with securities firm Jardine Fleming, then a senior vice-president at Temasek Holdings; Senior Counsel K. Shanmugam, who became Law Minister last year; cancer surgeon Ng Eng Hen, Education Minister; and Manpower Minister Gan Kim Yong, a former chief executive of listed company NatSteel.

'But we need more. And that's one of the priority tasks right now, looking for people like that,' said Mr Lee.

Read the full report in Tuesday's edition of The Straits Times.