In the 17 years since the Sydney Olympics, every Australian capital city with major sports content, except Sydney, has rebuilt old stadiums or constructed new ones.

Allianz Stadium, on the edge of Sydney's CBD, will no longer be guaranteed safe after 2018, while ANZ Stadium at Homebush in the city's west has been a compromised facility since it was built for the 2000 Games.

New digs: An artist's impression of what the new Allianz Stadium will look like. The stadium is built entirely on SCG Trust lands.

Should the NSW government cancel its plan to spend $2 billion rebuilding both stadiums, Sydney will be left with three facilities suitable for AFL (SCG, ANZ and the Giants' boutique stadium at Homebush) and two rectangular stadiums for rugby league, rugby union and soccer (an unsafe Allianz and a 30,000-seater at Parramatta).

This will leave Sydney in last place in the race among Australian capitals to stage major sporting events, such as grand finals, State of Origin matches, Bledisloe Cups and soccer's World Cup events.

Lights up: An artist's impression of a new Allianz stadium during a Roosters game. Supplied

Furthermore, the NSW capital will not compete on the world stage for events such as the FIFA 2023 Women's World Cup, the 2025 British and Irish Lions Tour, the 2027 Rugby World Cup, along with top music events.

The NSW government will be at the mercy of the major football codes, rather than the reverse. When the ARU was forced to decide between the Melbourne Rebels and the Perth-based Western Force to cut from its SANZAAR competition, the Victorian government told the code it would not release any money from its well-funded major events budget if the Rebels were axed.

Faced with no government support for Bledisloe Cup matches and visiting international teams for possibly a decade in Australia's second-biggest city, the ARU yielded to the Victorian government.

If, however, the NSW government reneges on its two stadia rebuild, the NRL will withdraw from the agreement to stage the next 25 grand finals in Sydney. With former Queensland premier Peter Beattie expected to replace John Grant as chair of the ARL Commission in February, NRL grand finals will be shopped around the country, with Brisbane's Suncorp Stadium a likely venue. The Queensland government has become more aggressive in the past five years bidding for events.

Big show: An artist's impression of a new Allianz stadium during a Waratahs game. Supplied

NSW has already lost to Queensland the status as dominant rugby league state, being beaten on most indices of success. The trend will continue unless fans of the Eels, Bulldogs, Wests Tigers and Rabbitohs fill modern rectangular stadiums, allowing these clubs to spend gate receipts on junior development.

Perth, with a new stadium and minus an elite rugby union tenant, will also join the bidding race. Western Australia is in the process of spending over $1 billion on a new sporting precinct.

Sydney has been under threat for more than a decade from Melbourne's easily accessible infrastructure, centring on the 100,000-seat MCG and justifying its self-proclaimed status as the sporting capital of the known universe.

As Destinations NSW chair John Hartigan says, "Sydney's position as the gateway to Australia is under threat from the twofold restrictions imposed by the limitations of Sydney airport [a curfew and shortage of slots] and the lack of facilities to attract world class events."

Hartigan points out that it will take 10 to 12 years to build a second airport at Badgerys Creek and the difficulties of attracting events to the city will compound in that time, should the two stadia not be built.

Tourism has moved from a tier-two revenue earner to tier-one status in Australia, particularly with the decline in mining.

Tourism is worth $33.2 billion a year to the NSW economy and it supports 164,000 jobs and more than 96,000 businesses in NSW rely on the sector.

Here we go again: ANZ Stadium in Homebush while still being built for the 2000 Games. Peter Morris

ANZ Stadium and Allianz Stadium, even in their current, inadequate states, host 200 major men's and women's fixtures across five codes every year and both venues attract 3.5 million people per year to major events and a total 17 million precinct visitors.

Allianz and ANZ, inject more than $1 billion into the NSW economy every year, meaning the initial $2 billion government investment is repaid in two years. If the state government doesn't invest in these facilities, it puts at risk the supply of critical revenue to NSW that funds schools and hospitals, as well as the jobs of one in 23 people who rely on the events sector.

NSW Sports Minister Stuart Ayres has pointed out the $2 billion stadia rebuild is a mere 1 per cent of the $200 billion the state government will invest in health and education over the period ANZ and Allianz are being rebuilt.

In other words, the 30-year investment in new stadiums is critical, not only for the long-term success of the visitor economy, but it helps fund health and education services all over the state.

Political football has already resulted in two key infrastructure projects in Australia – Melbourne's East-West Link and Perth's Freight Link – being cancelled because of electoral backlash. Transport experts say both will inevitably be built at a massively higher cost.

Kicking a hard decision down the road, like the NSW government's investment in the two stadia, only hurts the economy in the long run.