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

47. (1) No expenses shall, with a view to promoting or procuring the election of a candidate at an election, be incurred by any person other than the candidate, his election agent and persons authorised in writing by the election agent on account -

(a) of holding public meetings or organising any public display;

(b) of issuing advertisements, circulars or publications; or;

(c) of otherwise presenting to the electors the candidate or his views or the extent or nature of his backing or disparaging another candidate.

(2) Subsection (1) shall not -

(a) restrict the publication of any matter relating to the election in a newspaper or other periodical;

(b) apply to any expenses not exceeding in the aggregate the sum of one hundred dollars which may be incurred by an individual and are not incurred in pursuance of a plan suggested by or concerted with others or to expenses incurred by any person in travelling or similar personal expenses;

(c) apply to any expenses incurred in the holding of any meeting to disseminate political information or to promote the principles of a political party or a political or other association in cultivating the goodwill of a constituency.

Source: Article 47, Representation of the People Act, 1967 (updated 2015)

The limit 100 TTD exists for the individuals.  No limit for the expenses "incurred in the holding of any meeting to disseminate political information or to promote the principles of a political party".