Labor MPs have been running highly contestable and in some cases ''deliberately misleading'' advertisements for the national broadband network, experts say.

The Labor advertisements range from blatant falsehoods (saying the Coalition's NBN will cost $5000, while Labor's will be ''free'') to misleading comparisons (comparing the highest speeds possible under Labor's NBN with the minimum guaranteed under the Coalition's) and assertions (that the Coalition's NBN would not support high definition video conferencing).

Fairfax Media has reviewed Labor's NBN advertisements from around the country and found questionable claims in many of them. The Coalition has been running fewer NBN advertisements than Labor, but has made at least one highly contestable claim - after doing its own calculations, the Coalition said Labor's NBN would cost about $94 billion – adding some $50 billion to NBN Co's official figures.

The most contentious of Labor's NBN claims was by Families Minister Jenny Macklin, who said the Coalition's NBN would not support high definition video conferencing for e-health and education.