A defence lawyer for alleged lese majeste offender Daranee Charncherngsilpakul expressed concern yesterday that his client may suffer a negative outcome because she faces a closed-door trial.

Prawese Praphanukul said it was hard enough fighting a lese majeste case in the open, so having the trial closed to the public and media would make things even more difficult.

"Normally in an open trial [of such a case] the lawyer won't try to wrestle with the judges but if it's done in secret we will need to have legal assistants as witnesses."

Reporters and anyone not directly involved with the trial were barred from observing the proceedings, which began on Tuesday.

Daranee was arrested last July for allegedly defaming the monarchy in three separate speeches. She faces up to 45 years of jail if found guilty.

Her lawyer insists Daranee is innocent but conceded the chance of winning these cases was slim.

Prawese criticised the lese majeste law, saying it created more problems than it solved.

"I can't see that it's making society democratic ... as it ends up being a tool of opposing [political] groups," he said, referring to the fact that anyone can file a lese majeste charge against whoever they say has defamed the monarchy.

The 49-year-old lawyer also said it was not right Daranee had to wear a brown prison gown while in court. This type of attire was normally reserved for people accused of severe crimes, such as selling more than 10,000 methamphetamine tablets, he said.