Speaking at the party's first post-election news conference, Ataka party chief Volen Siderov told journalists on Sunday that the 400,000 Bulgarians who voted for his party were no fascists.
"They saw in us a defender of their interests … Ataka has won Bulgarians' confidence with its patriotic positions", Siderov said, hours after learning that his party would qualify for at least 22 seats – making Ataka as the fourth largest party in parliament.
Before results were announced, most analysts had described Ataka as a "fascistoid" and "ultranationalist" ethnic party that had found support by focusing negative attention on the country's ethnic Turkish regions.
Leading Bulgarian TV journalist, Niolay Barekov, had even referred to Siderov as a racist on Saturday - after his bTV channel showed an Ataka rally in which the party chief shouted out slogans against the Roma, Turks, Jews and homosexuals.
Ataka party officials have demanded an apology and say they will not appear on the channel until it is given.
But the local population to the south and north-east of the country – for centuries a mix of ethnic Bulgarian and Turkish peoples - have recently become the main battle ground for new parties such as the Democrats for Strong Bulgaria and Ataka.
However, one analyst has played down talk of a growth in ultranationalism.
Sofia University lecturer and political analyst Vassil Penev said he believed Ataka's new support came at the expense of the Bulgarian Socialists.
He said nationalist success should be considered more of a protest vote than a radicalisation of society.
Socialist leader Sergei Stanishev
may make an pact with MRF
"As soon as the possibility of a post-election coalition between the Bulgarian Socialist Party, led by Sergey Stanishev (BSP) and Ahmed Dogan, the leader of the [Muslim-minority] Movement for Rights and Freedoms (MRF), both party's were wide open to a major protest vote."
"I don't think people should read anymore into Ataka gaining over 8% in next parliament, even though it has become the fourth largest political force in the country. It is just an expression of disagreement with a BSP-MRF", Penev said.
Coming in third, behind the Socialists and the Simeon II National Movement, MRF's Dogan said his predominantly ethnic Turkish movement would always continue to support the "Bulgarian ethnic model because it is a European model".
Speaking to the Bulgarian news agency on Saturday, Dogan added that the responsibility for extreme phenomena such as Ataka in part rested on the country's political elite.
Meanwhile, MRF has sent more than 40 complaints for violations of the electoral law to the Regional Electoral Commission, mostly referring to people with permanent address who are absent from the electoral registers and whom the district election commissions refused to enter.
Those prevented from voting include the names of six mayors and all residents from the villages of Boyno, Chiflik and Enchets.
Coalition more likely
The results have led the NMSII to concede that the only viable government would group them with the Socialists and the MRF.
"Without the MNSII, the PSB and the MRF it will be difficult to form a government," outgoing Transport Minister Nikolai Vassilev told bTV television.
The party's campaign chief Lydia Shouleva added that it would "play an important and defining role in the political future of Bulgaria".
The Socialists won around 31% of votes in Saturday's poll, in which the MNSII lost half of its support to take just under 20%, according to a near-complete official count released on Sunday morning. The MRF polled 12.14% and Ataka 8.67%