The planned Kenya Kwanza parliamentary group meeting will happen on Wednesday morning.
The meeting, convened by President William Ruto, will be held at State House.
A section of UDA legislators who spoke to the Star confirmed they had been invited to the meeting.
"We have been asked to be there by 8am on Wednesday," said one of the MPs.
The 'crucial' meeting is happening at a time lobbying for the five slots to the East African Legislative Assembly (EALA) has intensified.
Among eyeing the seats in the party are David Sankok, Hassan Omar, Anne Too, Liliam Tomitom and Salim Busaidy.
Ruto is expected to use the meeting to whip the legislators to vote for specific individuals.
MPs are on Thursday set to conduct a vote to pick the nine MPs to the regional assembly.
