LDD leader Jean-Marie Dedecker, the former coach of the Belgian judo team, conceded that his party had been floored: "The result is a disaster".
"LDD could be left with only one seat in the Chamber of Representatives, very similar to the situation of the Flemish nationalist N-VA in 2003".
Mr Dedecker blamed the N-VA for his plight: “The N-VA has triggered a tsunami that swept away not only the furniture but also the house".
The LDD leadership meets on Monday and Mr Dedecker would not rule out a resignation.
LLD or Lijst Dedecker was set up as a right wing liberal party after the centrist liberals of VLD chucked Jean-Marie Dedecker out of the party.
LLD was represented in both the Flemish and Federal Parliaments, but is now losing between 2 and 4 percentage points across Flanders. Only in Mr Dedecker's home province of West Flanders is the party on course to pass the 5% threshold, but there too there are losses.
In the 2007 federal elections LDD polled a surprize 6%. It improved this to 8% in the Flemish elections last year.