SINGAPOREANS will get 50 per cent more in Growth Dividends cash on Oct 1.

On top of this, those living in HDB flats will also get 50 per cent more in utility rebates in November.

The higher-than-expected inflation and uncertain economic outlook have made it necessary for the Government to give $256 million more in aid, said Prime Minister Lee Hsien Loong who announced the higher payouts at the National Day Rally at the University Cultural Centre on Sunday.

He assured low and middle-income families in his English speech that the Government knows they are feeling the pinch of higher food, fuel and electricity prices, and is helping them to cope with rising costs. It has already promised $3 billion in help this year.

They include Growth Dividends cash - the first installment was given out in April following the large Budget surplus - and the Utilities-Save (U-Save) rebates introduced last year, to be given out annually for five years.

With this latest increase in aid, a low-income family living in a three-room flat will get $500 more, or $5,400 this year, while a middle-income household in a five-room flat will get $200 more, or $3,880.

The announcement was greeted with applause from the 1,700 guests at the UCC.

But Mr Lee cautioned about slower growth and greater uncertainties facing Singapore.

He said the problems in the global economy are starting to show up here in weaker exports, lower tourist arrivals and fewer guests in restaurants.

'I'm not predicting a crisis,' he hastened to add, noting that investors still want to come to Singapore, and a pipeline of projects like the Integrated Resorts will sustain the economy.

But he called for vigilance, in case of trouble, and readiness. 'We also must be on our marks, so when the global economy recovers, we can bounce right back.'

Turning to the cost of living hot-button issue, Mr Lee sought to explain what was within the Government's control - and what was not.

Inflation is not. It is a worldwide problem, compounded by the escalating oil and food prices in recent years.

To make his point, he flashed a series of slides showing people in France, Spain, Indonesia, Pakistan and the Philippines up in arms over higher prices and rice shortages, and blaming their governments for it. Then, for contrast, he flashed a slide showing Minister of State (Trade and Industry) S. Iswaran inspecting a stockpile of rice.

Mr Lee said, smiling broadly: 'Fortunately in Singapore, we have plenty of rice. So you don't see riots.'

He urged Singaporeans to 'react rationally' about the issue. 'We can't prevent prices from rising in Singapore.'