It depends on what you mean by "dishonesty"
Also - by "dishonesty" I mean saying stuff you know to be untrue, or pretending to be something that you are not, with the explicit aim of deceiving people.
Is there another meaning?
Note that I don't class as "dishonest" a refusal to cost policies, like the Tory refusal to cost their flagship Brexit policy, or Labour not having properly costed plan for their pension giveaway.
Not disclosing that sort of thing is not ideal - voters have the right to proper disclosure - but it's not "dishonest". "Dishonest" is lying about the cost, like for example the Chancellor claiming that there is no cost to the Brexit plan, when he knows this to be untrue.