43. Are there limits on the amount that third parties can spend on election campaign activities?

§ 1 Election committees shall have the right to nominate candidates for election. Electoral committees also perform other election activities, in particular, based on the principle of exclusivity, conduct campaigns for candidates
Source: Article 84 § 1, Election Code, 2011 (amended 2019)

§ 1. Election agitation may be conducted by any election committee and each voter, including collecting signatures supporting candidates' applications after obtaining the written consent of the electoral representative.
Source: Article 106 § 1, Election Code, 2011 (amended 2019)

The Election Code requires that all campaigns are financed through electoral committees. [...]
The Election Code permits campaigning to be conducted by any electoral committee and any voter, and prohibits campaigning by other entities without the consent of the electoral committee. However, a sanction for third party campaigning without the consent of the contestant was repealed in 2018, resulting in unclear regulation on the legality and consequences of such campaigning by legal entities and consequent reporting
OSCE/ODIHR (2020) Republic of Poland, Parliamentary Elections, 13 October 2019. OSCE/ODIHR Limited Election Observation Mission Final Report. OSCE/ODIHR, Warsaw

According to the Electoral Code election campaigns are financed exclusively through the electoral committees.

At the same time, the Electoral Code enables electoral agitation to be conducted not only by election committees, but also by voters. The Electoral Code does not contain provisions governing the financing of electoral agitation conducted by voters.