He made the comment after former United Front of Democracy Against Dictatorship leader Jatuporn Prompan said the House speaker post should go to Pheu Thai Party, the second-largest party in the eight-party coalition led by Move Forward.
The coalition is aiming to form the next government.
Previously, some Move Forward and Pheu Thai members, as well as supporters, feuded in public about which party should get to pick a House speaker.
Jatuporn has a right to express his political views, but a working group was set up to select a House speaker and it will do its job, Wiroj said.
He said the working group would deliver good news.
I have confidence that the process will be fair and democratic, he said, adding that the process was set up to ensure the people's interests are met.
Asked if he was worried that Jatuporn's comment would influence the process, Wiroj said he could not stop people from expressing their views.
When asked about the Election Commission's move to approve MPs next week, he said it would speed up the establishment of a new government and enable it to deal with corruption effectively.
Meanwhile, a source from the Move Forward Party said the name the coalition’s candidate to be the next House speaker will be announced at a press conference on Thursday.
There will be no conflict between Move Forward and Pheu Thai over the post, according to the source who also said that Move Forward needs to control the House speaker’s post to ensure it can implement the policies it promised it would, including amending the Constitution to be make it more democratic and promoting transparency in the House of Representatives.
One reason the name of the candidate cannot be named now is that Move Forward wants to allow Pheu Thai and other coalition partners to speak on the decision at the press conference, the source said.