By voting you give your consent to be governed by whichever political party wins.
When you disagree with the policies of all the parties, it is illogical to give any of them your consent.
Withdrawing your consent by not voting, is a valid way of dissenting.
If enough people refuse to consent to be governed, the political party which is declared the 'winner' can no longer claim to been granted 'consent to be governed'.
Consent of the governed - Wikipedia, the free encyclopedia