Appearing on Latvian Radio's Krustpunktā, he said that voter support for Unity is shrinking and that the vacuum is being filled by new forces.
"This is the last moment for Unity to get its act together, and to move from strife to cooperation, to elect a board, a chairman and define its vision," he said.
Ašeradens will vie against MP Edvards Smiltēns to become the party's chairman on Saturday.
Taking into account the party's low ratings, it might run with other political forces on the next Saeima election, slated for 2018.
Ever since the resignation of Prime Minister Laimdota Straujuma in late 2015, Unity has been anything but unified. Its dithering over naming a candidate to succeed Straujuma saw Maris Kucinskis of the Green and Farmers Union become prime minister instead and the party's poll ratings have plummeted.
Yet just a year before, Unity was riding high after successfully helping to oversee Latvia's six-month presidency of the European Union.
A poll carried out in May puts support for Unity just at 4% -- a rating that spells disaster for the party that holds 23 out of 100 seats in the Latvian parliament.
Former European Commissioner Andris Piebalgs has announced he is stepping down as party leader just a year after he took the job despite not being in the Saeima or indeed on a local council. His aim of securing 10% support for the formerly powerful party now looks hopelessly optimistic.
Several Unity MPs recently announced their decision to split from the party and become involved with a new centrist force currently known as 'Par!' (For!)