€13.8m-a-year given to parties and independents
Two taxpayer-backed funds provide the main political parties with the majority of their income.
The cash available from the funds - some €13.8m-a-year - dwarfs income from donations or corporate funding.
The first fund is known as the Parliamentary Activities Allowance, and can be claimed by parties and independents.
Until 2013, it was known as the Party Leaders Allowance.
It is designed to be spent by parties on their general administration, research, policy formation, polling and transport.
Parties are allowed to spend a portion on entertainment. It is also possible to pay the party leader a salary top-up, although Fianna Fáil is the only party doing so. Spending from this fund in 2014 amounted to €7.8m.
The sums available to parties are calculated on a sliding scale based on the number of members elected.
Each Independent TD can also claim an annual sum of up to €37,037, while non-party senators can claim up to €21,045.
Prior to mid-2014, independents did not have to account in any way for how they spent cash received from the fund. They now have to furnish an annual spending statement.
However, they do not have to produce receipts or invoices.
The second fund is known as electoral act funding and is available to the main political parties for general administration, research, education and training, policy formulation, and branch activities. In 2014, the sums spent by parties from this fund amounted to just over €6m.
The sum each party receives is in direct proportion to the number of first preference votes they received in the previous general election.
Between 2011 and 2014, Fine Gael received €8.1m from the fund, while Labour received €3.75m, Fianna Fáil €5.9m and Sinn Féin €2.5m.
The money cannot be used in connection with elections or referendums.