The leadership of ANO on Friday officially backed the policy programme and coalition deal reached with the Social Democrats on a planned minority government.
The Social Democrat top leadership is expected to do the same. The latter is also holding an inner-party referendum on whether the party should join the coalition.
The details of both the program and coalition deal were agreed upon by negotiators earlier this week and are due to be published.
On Saturday, the documents will be assessed by the Communist Party, whose backing will be required by the new government in a confidence vote and on key legislation, as the coalition lacks a majority in the 200-member Chamber of Deputies.