In all cases, the Barnett formula is a major focus – this is a mechanism used by the Treasury to calculate how much public money to allocate to Scotland, Northern Ireland and Wales, based on changes in spending levels. At the moment, the Barnett formula gives more per head to Scotland than to Wales.
The issue is a point of contention since Wales is much poorer than other areas of the UK, with average household income 14 per cent and nine per cent below that of England and Scotland, respectively.
So, what is each party promising ahead of the General Election next month?
Labour wants to give 16 and 17-year-olds the vote in Wales by May 2016. In terms of devolution of power, it plans to hand over control of fracking and aspects of transport such as the Wales and Border rail franchise, speed limits and ports.
In addition to this, Labour intends to deliver “fair funding for Wales” through the introduction of a Barnett funding floor, set at a level to reflect Wales's needs. This is essentially a guarantee that funding won't fall below a certain level.
This has been dismissed as not being good enough by Plaid Cymru candidate Ian Johnson, however. “A Barnett floor does not offer a lasting solution,” he said. “And if austerity continues then a Barnett floor will not generate any additional resources for Wales at all."
The Conservatives have also alluded to the introduction of a floor, but not much else. “This week George Osborne failed to even promise to maintain Wales’ funding at the current level,” Jenny Willott, candidate for Cardiff Central, commented following a recent visit by the chancellor to Wales.
Osborne said the Conservatives will seek independent experts and “talk to the Welsh Assembly Government about what the level should be”, referring to the floor.
He added that the party is already protecting Wales's funding, however, saying it is already “today at £115 spent in Wales for every £100 spent in England”.
The Lib Dems also want to guarantee funding for Wales will stay above an agreed minimum, using a Barnett floor that reflects the “country's needs”.
In addition, they intend to commission a study to help update the Holtham Commission's analysis, which estimated a £330m funding shortfall in Wales five years ago.
Ukip says it wants to "radically reform" the Barnett formula so finances to the devolved governments are calculated on the basis of need rather than population.
The intention is to increase payments to Wales, since they belive the formula currently unfairly favours Scotland.