An eye witness said Mwenefumbo was set to address the rally when an Aford activist invaded the venue and uprooted Aford flags, which were displayed alongside those of the UDF.
Police were called to settle the dispute, which Mwenefumbo described as "unfortunate and sad."
The Karonga Central legislator maintained that:" I am a loyal member of Aford and a citizen who is exercising his freedom of association despite being nominated to be the running mate to Atupele Muluzi of UDF.
He said he still recognizes Enoch Chihana as President of Aford.
Mwenefumbo and Chihana have in the past crushed over Aford leadership, both claiming to the leadership of the party that once swept all 33 parliamentary seats in the North. Chihana remains the sole Aford MP.
Muluzi picked Mwenefumbo as his running mate recently in a surprise move.