31. What are the provisions on 'ear marking' direct public funding to political parties (how it should be used)?

Article 24.2, ustawa o partiach politycznych 1997 (Law on Political Parties 1997, consolidated text 2023)
Art. 24.2. Majątek partii politycznej może być przeznaczony tylko na cele statutowe lub charytatywne.
English translation: 
“Art. 24.2. The assets of a political party may only be used for statutory or charitable purposes.”
Available at: 
https://isap.sejm.gov.pl/isap.nsf/download.xsp/WDU19970980604/U/D19970604Lj.pdf

Article 30.3-4, ustawa o partiach politycznych 1997 (Law on Political Parties 1997, consolidated text 2023)
Art. 30.3. Partia polityczna, która otrzymuje subwencję, przekazuje od 5% do 15% subwencji na Fundusz Ekspercki. 
4. Środki finansowe zgromadzone w ramach Funduszu Eksperckiego mogą być wykorzystane na finansowanie ekspertyz prawnych, politycznych, socjologicznych i społeczno-ekonomicznych oraz finansowanie działalności wydawniczo-edukacyjnej, związanych z działalnością statutową partii politycznej.
English translation:
“Art. 30.3. The political party that receives subvention transfers from 5% to 15% of the subvention to the Expert Fund.
4. The funds collected under the Expert Fund may be used to finance legal, political, sociological and socio-economic expertise, as well as to finance publishing-educational activities, related to the statutory activities of a political party.”
Available at: 
https://isap.sejm.gov.pl/isap.nsf/download.xsp/WDU19970980604/U/D19970604Lj.pdf

Direct public funding, as any other assets owned by a political party, can only be used for its statutory and charitable purposes, which certainly include campaign expenditures and ongoing operating costs.

In particular, a political party that receives subvention is obliged to transfer between 5-15% of this sum to its Expert Fund, which is aimed to finance legal, political, sociological and socio-economic expertise and publishing-educational activities.