Controversies have erupted and shots have been fired over the campaign period, as political parties worked to convince voters to lend support to their goals.

The Straits Times sets out the 10 issues that may weigh on voters' minds as Singapore heads to the polls on Friday (July 10).

1. Strong mandate v potential 'wipeout'

The ruling People's Action Party is calling for a strong mandate to see Singaporeans through the "crisis of a generation" with the Covid-19 pandemic, while opposition parties have raised concerns over a potential wipeout.

Which perspective is more likely to sway voters?

The PAP has set out the challenges Singapore is facing and its plans to overcome them, Prime Minister Lee Hsien Loong said in his online Fullerton Rally on Monday. Investors, and Singapore's friends and foes, will also scrutinise the election results and act on their conclusions, he said.

"Can we turn all these plans into reality? That depends. It depends on you giving a strong mandate for me and my PAP team."

But opposition parties, notably Workers' Party (WP) chief Pritam Singh, have warned of a possible opposition "wipeout", saying that holding the election during a crisis could sway voters to back the incumbent party. Even if the PAP loses one third of the 93 seats, it would still have a strong mandate, they said.

2. The Covid-19 impact

How will the Covid-19 pandemic influence voters' choice at the ballot box?

Opposition parties have criticised the Government's handling of the crisis and questioned its decision to hold the general election now. Some hot issues include the large number of Covid-19 cases in foreign worker dormitories, as well as the Health Ministry going back on its earlier advice to Singaporeans: that only sick people should wear face masks.

But the PAP points out how, since the start of the year, the Government has secured supplies of face masks, ramped up testing, and mobilised resources to deal with the infections in migrant worker dormitories.

Some observers have predicted a "flight to safety", given the looming economic downturn.

3. All eyes on the East Coast

Will Deputy Prime Minister Heng Swee Keat's presence bolster the PAP's results in East Coast GRC?

Mr Heng, the PAP's first assistant secretary-general, is poised to be Singapore's next prime minister. His move to helm the five-member East Coast team is viewed as a strategic decision to keep the GRC out of reach for the WP.

This year's general election marks the fourth time that the WP has contested in East Coast. In 2015, when the PAP won 69.9 per cent of the vote nationwide, its East Coast team got 60.7 per cent. The ruling party won with 54.8 per cent of the vote in 2011, and 63.9 per cent in 2006, the first year the GRC was contested.

4. The Tan Cheng Bock Factor

Dr Tan, 80, a former PAP MP who is now leading the Progress Singapore Party, is contesting West Coast GRC, which covers his former ward of Ayer Rajah.

Will his personal popularity be enough to win the constituency that garnered 78.5 per cent of the vote share in GE2015?

Dr Tan has been endorsed by Mr Lee Hsien Yang, the younger brother of Prime Minister Lee Hsien Loong and who recently joined the PSP. There was talk that Mr Lee Hsien Yang would contest the election but in the end he did not.

On the PAP side, West Coast GRC is helmed by Minister for Communication and Information S. Iswaran and Minister for Social and Family Development Desmond Lee. Mr Iswaran has taken aim at his opponents' manifesto, saying it contains broad statements but few details of the trade-offs involved.

5. 3G and 4G

How will voters respond to PM Lee's assurance that his party's senior leadership will stay on to help steer Singapore through the Covid-19 crisis?

Mr Lee has pledged that he and other senior PAP leaders - such as Senior Ministers Teo Chee Hean and Tharman Shanmugaratnam - will see Singapore through the crisis.

Although the fourth-generation leaders have, in Mr Teo's words, risen to the challenge in the past few months, some Singaporeans may feel more assured knowing the most experienced hands are on board as well.

6. Retirement of the old guard

Veteran politicians, including former Cabinet ministers and Workers' Party stalwart Low Thia Khiang, will not stand for election this year. How will voters respond to new faces and party renewal?

The ruling PAP has fielded a record 27 candidates this year, even as several heavyweights - among them Emeritus Senior Minister Goh Chok Tong, 79, - bid farewell to politics.

This year also marks the end of an era for more than one opposition party. Apart from the WP's Mr Low, 63, who surprised observers with his retirement, it will be the first general election since 1976 without either Mr Chiam See Tong, 85, or his wife Lina, 71, contesting.

7. New faces make news

Two new candidates - the PAP's Ivan Lim and the WP's Raeesah Khan - have come under the spotlight owing to their past behaviour. Could this affect the performance of their parties?

PAP new face Ivan Lim, 42, withdrew his candidacy even before the race began, after online allegations about his past behaviour surfaced a few days before Nomination Day.

And amid the campaigning, the police said over the weekend that two reports had been made against WP candidate Raeesah Khan for comments she posted on social media. Ms Khan, 26, has since apologised for the "insensitive" remarks. The WP has said it will review the matter after the GE.

But on both sides, the question remains: have these incidents left a bad taste in voters' mouths, and forced them to reconsider their votes on Polling Day?

8. An SDP revival?

Singapore Democratic Party chairman Paul Tambyah had a high profile during the election, perhaps even more so than party chief Chee Soon Juan.

Prior to the GE, Professor Paul Tambyah, an infectious diseases expert, had been in the news because of Covid-19. He also recently became the first Singaporean to be picked to head the International Society of Infectious Diseases.

During the campaign, SDP became embroiled in a dispute over a 10 million population target it accused the PAP of "toying with". The PAP rejected this suggestion as a falsehood and a straw man aimed at misleading and frightening voters.

Would the controversy affect the party's showing?

9. The NCMP question

How will the debate over the Non-Constituency MP (NCMP) scheme figure in voters' minds?

The NCMP scheme had been the subject of much debate in the lead-up to this year's general election, with opposition parties criticising it as a ploy to entice voters to vote for the PAP.

But the ruling party has countered that the scheme guarantees a "significant opposition presence" in Parliament, regardless of what happens in the general election. Given this, PM Lee said, Singaporeans should not vote for "compromise candidates".

The Constitution guarantees at least 12 opposition members, with equal voting rights as elected MPs, in Parliament under the NCMP scheme, which provides for seats to be reserved for losing opposition candidates with the highest vote shares.

10. A Digital Election

Have online rallies and televised constituency political broadcasts proved an effective replacement for physical rallies?

Barred from organising traditional mass rallies, political parties have been given more airtime on national television and turned to the Internet to engage voters.

But there was no denying the importance of human contact. All candidates spent long hours working the ground, at markets, hawker centres and home visits- with masks firmly in place and trying their best to maintain safe distancing, which was often difficult.