I wonder which Sophie Mirabella story last week annoyed Liberal party HQ more: that she told voters in Indi they missed out on $10m local hospital funding as punishment for not re-electing her, or the claim that she shoved her opponent, independent MP Cathy McGowan, out of a photo with assistant health minister Ken Wyatt (which Mirabella strenuously denies).

These things remind us that campaigns often face unplanned events and uncontrollable circumstances. And the longer the campaign, the greater the likelihood is of stepping on a political land mine.

Often it’s the unexpected that explodes. But not all risks are unknown. As Malcolm Turnbull prepares to lead his troops into a 10-week battle, there are five potential ticking time bombs. If he’s lucky, none of them will go off.

And he will need luck, because there is very little he can do about any of them.

The banks

Last week Turnbull and his treasurer Scott Morrison stuck their necks out for the big four banks. With Labor’s proposed banking royal commission winning majority support with voters, the Coalition realised Australians are fed up with a string of scandals in financial institutions and expect someone to do something. Turnbull and Morrison announced more money and new powers for the Australian Securities and Investment Commission.

Turnbull argues that Asic will get results now while a royal commission won’t produce anything for several years. Even though Asic won’t get its new funding until after July, that argument might work – but not if another banking scandal breaks before the election. If that happens Asic will (fairly or not) go from being the “tough cop on the beat” to the keystone cops, and Turnbull, the former investment banker, will look like he’s been protecting his mates.

The triple-A credit rating

The ratings agency Moodys has issued a clear warning: if the current budget trajectory continues, Australia could lose its AAA credit rating. Moodys says it expects the 3 May budget to include revenue measures as well as spending cuts. A downgrade would be catastrophic for a Coalition government pitching themselves as better economic and financial managers.

Ratings agencies usually make pronouncements within 72 hours of a budget, so Turnbull won’t need to wait long to find out if he’s escaped unharmed. This is the risk Turnbull is most able to manage. However, his options are limited because of all the new tax measures he’s taken “off the table.”

Mal Brough, Wyatt Roy and Christopher Pyne

The Australian Federal Police are investigating the unauthorised copying of former speaker Peter Slipper’s diary by James Ashby. Liberal MPs – and Turnbull backers – Mal Brough, Wyatt Roy and Christopher Pyne are assisting police with their inquiries. Brough’s home was searched by the AFP in November, and he last reportedly spoke with the AFP on 7 January.

On 29 February, after Sky News broke a story about AFP removing evidence from the federal parliament, the AFP confirmed it had been conducting enquiries with the department of parliamentary services in relation to “an ongoing investigation” – but did not confirm what that investigation is. Brough stood down from the ministry in December and is not contesting the election. Roy and Pyne are front-benchers. At best the AFP dismisses the case during the election campaign. At a minimum, Turnbull hopes the AFP makes no moves in any direction. At worst, the investigation advances to further raids or even arrests.

Arthur Sinodinos and the NSW Liberal party

Turnbull’s cabinet secretary, Senator Arthur Sinodinos, sits squarely on the centre of a giant mess in the NSW Liberal party. Sinodinos was honorary treasurer and finance committee chairman when the NSW Branch was washing funds, according to the NSW Electoral Commission, from prohibited donors through the Liberal-aligned Free Enterprise Foundation. The NSW Electoral Commission refused Sinodinos’ appeal to have his name removed from its rulings on the matter.

A number of hand grenades sit waiting to explode: there’s the $4.4m the NSW Electoral Commission is withholding from the NSW Liberal party; that lost funding has real consequences on the branch’s ability to run a federal campaign. The Free Enterprise Foundation may turn over its list of donors, which could generate further explosive and embarrassing revelations. Now the Senate has called an inquiry and is subpoenaing Sinodinos next week. And for added kick, the NSW Icac could anytime release its overdue report on the whole matter, which would surely include its observations of Sinodinos’ performance and reliability as a witness.

Tony Abbott

When he left the prime ministership Abbott promised no sniping and no undermining. Instead he’s been ever so helpful, regularly pointing out the continuity between his government and Turnbull’s. He also is using a series of Quadrant essays to reflect on his own government’s successes and failures.

Frustratingly for Turnbull, no doubt, last weekend the media spent more time dissecting Abbott’s self(ish)-observations than celebrating the government’s changes to the dental care scheme. Surely it won’t be the last time this campaign that Abbott out-flanks Turnbull on the battlefield.