The Legislative Assembly, Civic.

The Legislative Assembly building in Civic. A pressing issue is where to house the eight extra members. Photo: Melissa Adams

A boost to the number of MPs in the Assembly would allow the main political parties to spend vastly more on election campaigns, unless they change the spending cap.

At the moment parties can spend an average of $60,000 per candidate on campaigns, to a maximum of the number of Assembly members. With 17 seats, as it now stands, that limits the parties to about $1 million. But with another eight candidates in the mix, the parties would each be able to spend up to $1.5 million each.

That would put major party spending well out in front of minor parties and independents who lack similar income sources.

This is just one of the questions the MPs will have to grapple with as they work through the detail of an increase from 17 members to 25 for the next election.

As well as their own funding sources (membership, business donations, investments, and for Labor, licensed clubs and unions), the big parties get the bulk of public funding after each election. At the last election, the amount was $2 for each first-preference vote, amounting to $172,000 for each of Labor and Liberal and $48,000 for the Greens.

From their own sources, ACT Labor received $2.1 million in 2011-12, and the Liberals $732,000. The Greens received funding of $204,000 from private sources. In the 2012 election, Labor spent just short of the $1 million limit, at $920,000. The Liberals spent $737,000, and the Greens $227,000.

Chief Minister Katy Gallagher said the funding cap was one of many issues to be worked through once the Assembly passed legislation to make the shift from 17 to 25 official - probably about mid-year.

Greens convener Sophie Trevitt said the party was still considering the ramifications of the change and whether it would create an equity problem for smaller parties and independents.

A pressing issue is where to house the eight extra members, with thought being given to shifting ministers' offices out of the main building on London Circuit into another building nearby - a shift that Ms Gallagher said would be sensible, given that ministers did not need to be in the Assembly building for their day-to-day work. ''I'm conscious that people expect us to do this on the leanest possible budget, so that's where I'm coming from,'' she said.

And at the end of this year, the ACT Electoral Commission is set to begin work on redrawing all the electoral boundaries, to create five electorates instead of three.

Assembly members are already keen to see where the boundaries will be drawn so they can begin to get to know their new electorates well ahead of the next election.