Talk that the general election might be held in September has gathered pace, with the boundaries report out last Friday and voter rolls now open for public inspection.

The date most cited, and already spreading like wildfire in text messages and on social media: Sept 12.

The Prime Minister has the prerogative to decide when to call an election. But one clear sign that the polls might be called soon was People's Action Party organising secretary Ng Eng Hen's comments on Sunday that the party is likely to begin formally unveiling new candidates after National Day.

Add the feel-good effect of Singapore's golden jubilee celebrations and a National Day Rally on Aug 23 for PM Lee Hsien Loong to give a "last rallying call and present the (Government's) report card", and that is why veteran MP Inderjit Singh thinks: "Things won't get sweeter than that from the Government's perspective."

He agreed a Sept 12 date looks likely. It is the last Saturday of the week-long school holidays.

Schools are typically used as polling stations, and teachers tapped to man these stations.

Mr Singh, an MP of 18 years, said yesterday that he sees "no point delaying it until the end of the year".

"The major policies are out of the way, there is nothing new to be announced, and when that happens, it means the party has already delivered what it has promised."

He noted that the goods and services tax vouchers will be given out next month to those who qualify.

In past elections, Parliament was dissolved within two months of the release of the boundaries report.

Parliament will next sit on Aug 17. That could be its last session should it be dissolved in the week after the National Day Rally. Going by the timeline of the 2011 election, this could mean the Writ of Election would be issued on Aug 26. That would point to Nomination Day - which must be at least five working days from the date the election writ is issued - falling on Sept 2.

It would mark the start of the traditional nine-day campaign period until Sept 10. Cooling-Off Day would be on Sept 11, with voters heading to the polls on Sept 12.

That weekend period in September is the most likely because Singapore's Formula One Grand Prix takes place from Sept 18 to 20.

School examinations rule out October and early November as windows for an election. And the second half of November is a busy period of global summits which involve PM Lee and other ministers.

The question now, said political observer and former Nominated MP Eugene Tan, is whether Mr Lee will buck the trend of dissolving Parliament within two months of the boundaries report being released.

"If you go by precedent, it would suggest that elections are likely to be in September. But that precedent is not binding.

"It is also likely that the rather early release of the report and PM's getting it published immediately only means he is keeping to his assurance to Parliament, to make sure enough time has elapsed between the report's release and the polls."