Liberals Speaker Vicki Dunne has instructed MLAs to refer to Mr Seselja only by his name in the Assembly chamber and, specifically, not to call him ''senator elect''.

The move follows weeks of attacks by government MLAs, who have tried to force Mr Seselja to quit the Assembly since he won the ACT Liberal Party's number one Senate nomination.

The government has repeatedly referred to ''Senator Seselja'' and ''senator elect'' in its criticism of the Canberra Liberals MLA, who is yet to specify the date when he will leave the Assembly to campaign for the federal election.

In an email to Labor MLAs, party whip Mick Gentleman said Mrs Dunne, in an administration and procedure meeting, had ''asked members not to refer to Mr Seselja by any other name in the chamber''.

''Specifically, Madame Speaker asks members not to refer to him as 'Senator Elect,' '' the email says.

Mrs Dunne, who has given similar instructions in the Assembly chamber, said she was enforcing the rules of debate in the Assembly.

In February, ACT Labor and Greens MLAs passed a motion condemning the Canberra Liberals MLA for ''betraying'' Tuggeranong voters after he announced he would contest the Senate four months after he was re-elected to the Legislative Assembly.

In the chamber this week, the former opposition leader was pressured by Deputy Chief Minister Andrew Barr and Chief Minister Katy Gallagher, who spoke of ''the member in the departure lounge'' during heated debate on Wednesday.

Ms Gallagher joked Mr Seselja had spent two days in the chamber this week signing ''thank-you cards, or bon voyage cards''.

''I find it very difficult to sit through a lecture from Mr Seselja, who has already signalled his intention he has no more interest in matters in this place,'' she said.

Ms Gallagher said government MLAs had been advised to refer to the Liberals MLA by his correct title.

''To [Mrs Dunne's] defence, she has said that in the chamber as well,'' she said. ''This was unusual in it's like another reminder. We take those warnings pretty seriously. We won't change our view that he shouldn't be sitting in the chamber … but we have to respect the chair as well.''

Mrs Dunne said ''the rules of debate for the Assembly require all members to refer to their colleagues by their proper name or title and the Speaker has no choice but to enforce that rule. I do it to members of all parties on a regular basis. ''While it usually causes little offence, such as here, name-calling is a silly practice that adds very little to any debate.''