Campaigner George Elkington was appealing his conviction in the Magistrate's Court in March for not having a TV licence.
Advocate Peter Ferbrache said his client was not an eccentric millionaire but an ordinary man who felt aggrieved at being prosecuted for not paying what he considered to be an English tax.
His challenge was based on the fact that the Human Rights Convention that was adopted in the Bailiwick in 2006 did not allow for the imposition of a UK tax.
Crown Advocate Chris Dunford said it was irrelevant to talk about Guernsey not being represented in the UK Parliament as this was a UK act that had been extended to the island.
Judge Russell Finch will give his judgment later.
