Joseph Kelly, 35, has pleaded not guilty to sending the message "of an indecent, obscene or menacing character" about the fundraising centenarian on February 3.
The tweet said "the only good Brit soldier is a dead one, burn old fella burn".
During legal discussions at Lanark Sheriff Court on Thursday, Kelly's defence advocate Cameron Smith lodged "incompatibility" and "oppression" minutes with the court.
He said: "The tweet was made in the aftermath of the passing of Captain Sir Tom Moore.
"The minute does not dispute that he did in fact author and post this tweet to his Twitter account, however this is the case where his fundamental rights are guaranteed under the European Convention on Human Rights."
He said prosecution could breach those rights, and the term "grossly offensive" is so vague and broad it cannot meet the requirements of accessibility and foreseeability under the convention.
Kelly, of Castlemilk, Glasgow, is on bail and was not in court for the hearing.
The charge under the Communications Act alleges that Kelly "did cause to be sent by means of a public electronic communications network a post to the public using social media that was grossly offensive or of an indecent, obscene or menacing character, and that did utter offensive remarks about Captain Sir Tom Moore, now deceased".
A trial has been fixed for January 31.
Sir Tom, who captured the hearts of the nation with his fundraising efforts during the first coronavirus lockdown, died in Bedford Hospital on February 2 after testing positive for Covid-19.
He walked 100 laps of his garden before his 100th birthday, raising more than £32 million for the NHS.
The court hearing before Sheriff Adrian Cottam continues.