Prosecutors say former federal MP Craig Thomson must go straight to prison for misusing his Health Services Union credit cards.

Prosecutor Lesley Taylor SC said Thomson had not uttered a single word of remorse for the 65 dishonesty offences he committed while he was the union’s national secretary and a Labor MP.

She said Thomson was “arrogant in the extreme”.

“He has uttered not one single word of remorse,” Taylor told the Melbourne Magistrates Court on Tuesday.

Thomson used HSU cards to pay for escorts and make cash withdrawals.

Thomson has agreed to repay the $24,538 he misused, his lawyer Greg James QC told the court.

James said Thomson was suffering a major depressive illness and urged Magistrate Charlie Rozencwajg not to impose a prison term.

He said Thomson’s offending was opportunistic and happened during a time in which his relationship with his wife was breaking down.

“He sought comfort elsewhere,” James said.

Taylor rejected James’ suggestion that the offending was opportunistic.

“It was selfish and done for his own gain and his own gratification,” she said.

Taylor said Thomson had hurt the entire trade union movement.

“His corrupt behaviour has damaged the reputation of all of them,” she said.

Thomson last month was found guilty of 65 dishonesty offences over his payments to prostitutes, personal expenses and cash withdrawals.

James said most of the offending occurred when Thomson was a senior official in the union, before he became a member of parliament.

James said a full-time custodial sentence was not mandatory and there were other options that better suited the matter.

Rozencwajg will sentence Thomson on March 25.