The battle lines of the election have been drawn: the Coalition is focusing on economic management and promises of bigger tax cuts for middle and high-income earners; Labor is promising higher social spending and wage growth.

But beyond the daily announceables there are many policy areas the major parties are less keen to talk about.

Some will affect election costings – so the parties will have to give answers by 18 May. But others risk slipping below the radar until after election day.

Here are some of the known unknowns of the federal election campaign.

What is the Coalition’s industrial relations policy?

The Coalition has released a “union accountability” policy that says it opposes Labor’s plan to abolish the Australian Building and Construction Commission and Registered Organisations Commission.

Beyond that? Not much.

In 2015, the Productivity Commission reviewed workplace relations laws. It contained ideas such as an “enterprise contract”, which could undercut award wages and force new workers to sign up to conditions on a take-it-or-leave-it basis.

Michaelia Cash said the government would respond to the Productivity Commission’s review of workplace relations laws ‘in due course’. Photograph: Mike Bowers/The Guardian

Before the last election, the then employment minister, Michaelia Cash, said the government would respond to the review “in due course”. But the Coalition never responded, disheartening employer groups and leading unions to argue it had no mandate for reform.

The RMIT labour law academic Anthony Forsyth told Guardian Australia the Coalition was “clearly still spooked by WorkChoices, they don’t want to touch this area”.

Don’t hold your breath for any announcement before election day, but it’s worth noting the government has never formally ruled out changes.

Labor has released a lot of policy in this area but key details of its policy are also still missing: which workers will get access to multi-employer bargaining? Will rules restricting strikes be relaxed, given Labor has said laws must comply with International Labour Organisation standards?

“Labor will have more to say on workplace relations policies before election day,” a campaign spokesperson has promised.

Labor wants more money for aid and Newstart – but how much?

Labor’s policy is to review Newstart, and Bill Shorten has said the unemployment benefit is currently “too low”.

Because the review will only be conducted in government, if Labor is elected, the party has not committed to a specific dollar increase and we won’t know what’s proposed before election day.

On foreign aid it’s a slightly different story – foreign affairs spokeswoman Penny Wong has said Labor will increase aid as a proportion of gross national income in the first budget and every year afterwards.

Labor also has a long-term ambition of reaching aid equal to 0.5% of GDP, but that won’t be achieved in the first term of government. The increased spending on aid will be revealed in pre-election costings, Guardian Australia understands.

How would the Coalition prevent religious discrimination?

Before the election campaign the attorney general, Christian Porter, revealed the Coalition would not release its new religious discrimination bill before the election.

LGBT rights groups agree in theory that discrimination on the basis of religion should be outlawed, but have warned that the law must be a “shield, not a sword” against LGBTI people.

In responding to the Ruddock review, the government also promised a separate omnibus bill to amend other discrimination laws to provide “equal status” to freedom of religion alongside the right to non-discrimination. That could be highly controversial.

The government has set up an Australian Law Reform Commission review to look at the contentious issues of religious schools’ right to discriminate against LGBT students, so the reform proposal there will also be unclear on election day.

More to say on climate change and the Adani coalmine

Labor has been criticised on the campaign trail for not releasing estimates of the cost to the economy of its climate policies.

Anti-Adani protesters dressed as Bill Shorten and Scott Morrison. Labor is refusing to say definitively if it will review Adani’s approvals if it wins government. Photograph: Joel Carrett/AAP

That is a bit of a red herring because it depends how companies can abate greenhouse gas emissions, but it is true there are some details missing: will there be limits on the quantity of international permits that can be used to meet emissions reduction targets? How will Labor assist trade-exposed industries?

Labor has also been tiptoeing around Adani’s Carmichael coalmine – building a case to review the approval of the mine’s groundwater management plan but refusing to say definitively if it will review Adani’s approvals if it wins government.

On Tuesday, Bill Shorten said Labor had “no plans to review the approvals” but also did not rule it out. So that will likely be a decision that is left to government, if Labor is elected.

Both sides missing details on education

The Coalition has initiated a review to design a performance-based funding system for universities. The consultation paper for the review suggests the performance-based component would start small – just $70m of the $7bn given in commonwealth grants – but could grow to $210m by 2023. Universities would have to wait to find out how the new system would work.

Batman MP Ged Kearney and Labor’s education spokeswoman, Tanya Plibersek, with Preston West primary school students in Melbourne. Photograph: David Crosling/AAP

Labor has promised an additional $14bn over 10 years to public schools, with $3.3bn spent in the first three school years, and to match the Coalition’s funding for non-government schools, which totals $4.6bn more over a decade.

Labor says that, by the end of the first three years, public schools in every state and territory would get 22.2% of the schools resourcing standard. But the exact division of funds would depend on new agreements with the states and territories, and non-government school sectors.

Of particular note is the Coalition’s $1.2bn “choice and affordability fund”, which Labor’s education spokeswoman, Tanya Plibersek, said looks like a “slush fund” for independent and Catholic schools. Labor is committed to the same funding quantity – but has not said if it will draw up new rules about the distribution of this fund, or if it will scrap it.

Home affairs minister and national integrity commission

Labor has committed to review the home affairs portfolio, which could lead to Peter Dutton’s super department being broken up.

But in February, when Shorten was asked if Labor “will” or “wants to break it up”, he replied: “No. First of all, I want to change the minister.”

Labor has released design principles for its national integrity commission but further work is needed to create a detailed model.

The former chairman of Transparency International, Anthony Whealy, told Guardian Australia that Labor was off to a good start by committing to an independent integrity commission, with wide jurisdiction and the powers of a royal commission.

But Whealy said, if elected, Labor would need to give “much more” than the $58.7m over four years it has committed so far, and he would recommend $100m a year ($400m) to set it up.

Whealy said Labor was also yet to determine the test for when the commission can hold a public hearing, and how to protect the reputation of people it would investigate.

Labor says the “final costs of the national integrity commission will be determined when the specific design work is undertaken, following a consultation process”.