Premier Jay Weatherill's lawyers have sent a cease and desist letter to an Adelaide man who has been driving around in a van emblazoned with the words "Jay Weatherill: Premier For Best Liar".

Vincent Scali, who has signalled his intention to run against the Premier in his seat of Cheltenham, told the ABC he had received the letter today.

The letter from Bourne Lawyers, supplied to the ABC by Mr Scali reads:

"Your conduct is obviously deliberate and calculated, designed to expose our client to public odium, scandal and contempt. A further aggravating factor is that your conduct breaches the Electoral Act 1985.

"Our client demands you immediately remove the defamatory material from your van and cease and desist from further defaming him."

Earlier Mr Scali told the ABC he intended to legally change his name to 'Hadd Enuf'.

The Electoral Commission has already sent a letter to Mr Scali as a result of a complaint from Mr Weatherill, warning him that the van breaches rules around electoral advertising.

Mr Scali is a former candidate for the Palmer United Party.

In 2015 he won a defamation lawsuit against his brother who accused him of being a "fraudster" and a "psychopath".

Vincent Scali's van, which he has been driving around Adelaide. ( ABC News: Wendy Glamocak )

Mr Vince said he was not deterred the by the letter and still intends to run in Mr Weatherill's seat.

"I'm a street fighter and I'm not intimidated and I've written back to the Premier's legal people and I've said I won't be intimidated by Mr Weatherill's letter. As a matter of fact my resolve will be greater," he said.

"I've had some legal advice on my van and apparently there is a technicality in the law that I can drive around in it and make it perfectly legal with a couple of minor adjustments.

"It'll be back on the road when I get back with some minor adjustments.

"My name will be Hadd Enuff and they'll have the opportunity to vote for me in the seat of Cheltenham, remembering it wasn't so long ago there was a Prime Minister called John Howard who was unseated."

Mr Weatherill has declined to comment.