2. Is there a ban on donations from foreign interests to candidates?

Section 9. (1) A list of candidates may be submitted by:
1) a political party registered in accordance with the procedures laid down in law which has been
established not later than one year before the election of the Saeima and which has at least 500 members;
2) an alliance of political parties registered in accordance with the procedures laid down in law if all
political parties belonging to the alliance of political parties have been established not later than one year
before the election of the Saeima and if the alliance of political parties has at least 500 members.

Law on the Election of the Saeima, Article 9 (1) (2).

No donations to individual candidates allowed; no individual candidates stand for elections, only party lists. 
Therefore, while candidates may engage in individual pre-election canvassing campaigns (see Law on Financing of Political Organisations, section 8⁴, 4), all donations must be directly transferred to the respective political party. In other words, no donations to individual candidates on the party lists are allowed.